Understanding Cardiomyopathy: Epidemiology, Risk Factors, Types, Mechanisms, Diagnosis, Prevention, and Treatment

Abstract

Cardiomyopathies (CMPs) encompass a heterogeneous group of cardiac disorders affecting mainly many of the elderly populations globally. Clinical presentation of cardiomyopathy varies among patients, based on the type and severity of the disorder. Preventing cardiomyopathy involves a multifaceted approach. Management strategies for cardiomyopathy encompass a spectrum of interventions. Medications, including beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, diuretics, and anti-arrhythmic drugs, are commonly prescribed to patients. Device implantation, including pacemakers, implantable cardioverter-defibrillators (ICDs), and ventricular-assist devices (VADs), is necessary in some cases. Lifestyle changes, including dietary modifications. Reduction in alcohol consumption, smoking and stress level, weight management, and regular exercise programmes, are essential components of adherence to self-care. Surgical interventions may be considered, including cardiac surgery and, in severe cases, heart transplantation. This review provides a thorough understanding of cardiomyopathy, covering a wide range of crucial aspects, including epidemiology, risk factors, types, subcellular and molecular mechanisms, clinical presentation, diagnostic approaches, treatment modalities, and prevention strategies, a profound understanding of these aspects is essential for healthcare professionals and researchers to enhance patient health care.

1. Introduction

Cardiomyopathy is a severe medical condition, which can lead to functional impairments and structural abnormalities in the heart muscle. Cardiomyopathy is characterized by a variety of changes, including myocyte hypertrophy [1], interstitial fibrosis which is a key player in cardiomyopathy that involves the excessive deposition of collagen and other extracellular matrix (ECM) components [2], increased oxidative stress, mitochondrial and endothelial dysfunctions, altered myocardial excitation-contraction coupling (ECC) process, necrosis, and remodeling of the myocardium [3]. These pathophysiological alterations further weaken the myocardium and diminish its ability to pump blood efficiently around the body to meet constant demand [4]. Progressively, these processes disrupt the normal architecture of the myocardium, hindering efficient electrical signal conduction and coordinated contraction [5]. These changes lead to cardiomyopathy manifesting in several distinct forms or subtypes, including dilated (DCM), hypertrophic (HCM), restrictive cardiomyopathies (RCM) and arrhythmogenic right ventricular cardiomyopathy (ARVC) being the primary classifications [6]. Each type exhibits specific pathophysiological traits. For example, dilated cardiomyopathy shows ventricular dilation and systolic dysfunction, whereas hypertrophic cardiomyopathy is characterized by myocardial hypertrophy, potential outflow obstruction, and diastolic dysfunction. Likewise, restrictive cardiomyopathy involves stiffening of the myocardium, leading to impaired ventricular filling [7]. Finally, ARVC is related to a group of clinical conditions that are characterized by right ventricular fibrofatty infiltration, with a predominant arrhythmic presentation [6]. Cardiomyopathy contributes markedly to morbidity and mortality worldwide, with an impact that extends from the individual patient to the broader healthcare system [8]. This cardiovascular disease is associated with a reduced quality of life of the patients due to the limitations imposed by heart failure symptoms. As such, cardiomyopathy demands a multidisciplinary approach in diagnosis, management, treatment, and research into its development, making it a focal point for advancing cardiac health and patient healthcare outcomes.

2. Aim of this review

The purpose of this literature review is to synthesize and examine the current state-of-the-art knowledge regarding cardiomyopathy, its epidemiology, risk factors, types, subcellular and molecular mechanisms associated with pathology of development, clinical presentation, diagnostic approaches, treatment modalities, and prevention strategies. The review is also related to clinical implications to contribute to the existing body of literature by providing a comprehensive overview that encapsulates recent findings and perspectives. It seeks to highlight the complexity of cardiomyopathy, underscore the importance of ongoing research in this area, and identify potential areas for future study. The significance of this work lies in its potential to inform and guide clinical practice, enhance patient care, and direct future research endeavors. This literature review is not only a scholarly exploration but also a step towards improving patient outcomes in cardiomyopathy, thereby playing a critical role in the evolution of cardiovascular medicine.

3. Epidemiology and risk factors

In 2021, 2,268,240 cases were reported to develop dilated cardiomyopathy (DCM), the most common subtype of cardiomyopathy, especially in the USA, France, Italy, and the United Kingdom, with the number increasing annually by 2% [6]. Moreover, the burden of cardiac disorder on global health is substantial, with current epidemiological studies reporting its prevalence at approximately 2.5 million individuals in the United States and over a quarter of a million in the United Kingdom, contributing to a worldwide prevalence estimated at 6 million for all subtypes of cardiomyopathy [6, 9]. The actual incidence of cardiomyopathy is potentially higher than what is recorded, due to its asymptomatic progression in a subset of patients, which can lead to a delay in diagnosis. This under-recognition is emphasized by cardiovascular diseases being responsible for an estimated 18 million deaths per year globally, both in developed and low- and middle-income countries. The epidemiological statistic is steadily increasing and to which cardiomyopathy is a significant contributor, as reported by the World Health Organization (WHO) [6, 10]. This pathology exhibits either no age, religious, or ethnic selectivity. Moreover, accurately quantifying the global incidence of pediatric cardiomyopathy presents a complex challenge, compounded by the heterogeneity of healthcare infrastructures and the variable robustness of epidemiological surveillance across different nations. These estimates suggest a global prevalence of 5–10 cases per million children under 18 years old [11], with potential peak incidences that occur in infants under 1 year [12] and adolescents [13]. Like adults, children can face various types of cardiomyopathies, with dilated cardiomyopathy (DCM) dominating at 35–50% of cases, followed by hypertrophic cardiomyopathy (HCM) at 20–30%, ARVC at 15%, and restrictive cardiomyopathy (RCM) at 5–10% [11].

The etiology of cardiomyopathy in adult and pediatric is multifactorial, encompassing an array of risk factors that converge to precipitate this myocardial pathology. Cardiomyopathy is a complex cardiac condition with a multifactorial etiology, involving a range of interconnected risk factors that contribute to its development. Figure 1 provides a concise visual representation of these diverse contributors, emphasizing their interplay in the pathogenesis of this condition. Risk factors are diverse, and they serve as essential resources for clinicians, researchers, and public health professionals seeking to mitigate the impact on the development of cardiomyopathy. By integrating the latest research findings with clinical insights, this work aims to catalyze the development of advanced management strategies for cardiomyopathy. Ultimately, this endeavor seeks to contribute a substantial and meaningful advancement in the fight against one of the most challenging cardiovascular diseases, thereby fulfilling a critical need in contemporary medical science and patient health care.

Figure 1.

Diagram illustrating some of the risk factors that are associated with the development of cardiomyopathy or disease of muscle within the heart (drawn by hand).

4. Subcellular, cellular, and molecular mechanisms

The complexity of cardiomyopathy is further compounded by its multifactorial aetiologies that require a deeper understanding of its varied subcellular, cellular, and molecular dimensions during its development over time. Cellular changes involve remodeling processes that alter the heart muscle’s architecture, leading to a compromised contractile apparatus and inefficient cardiac output. One of the critical consequences of cardiomyopathy is heart failure (HF), a condition where the ability of the heart to pump blood effectively is compromised. The progressive loss of cardiomyocytes is due to many pathways related to either necrotic, apoptotic, or autophagic cell death, part of which is highly regulated and programmed [14]. This loss of cellular integrity and function in the heart muscle is a pivotal factor in the progression towards HF, which in itself is a progressive condition originating from myocardial injury due to ischaemia/reperfusion and myocardial infarction due to different health risk and biochemical factors. This injury leads to subcellular and molecular changes manifesting as structural remodeling of cardiomyocytes [15]. This remodeling is characterized by changes in size, shape, and the arrangement of the cells, resulting in impaired contractile function and increased ventricular stiffness, characterized by net accumulation of extracellular matrix proteins in the cardiac interstitial tissues resulting in fibrosis [16, 17]. This, in turn, contributes to both systolic and diastolic dysfunction as in many heart debilitating conditions [16]. One of the key features in this process is the disruption of cardiomyocyte calcium handling via derangement in calcium transporting proteins that in turn, impair the ECC process and contractile function of the heart [18]. Furthermore, oxidative stress leads to increase in reactive oxygen species (ROS) and reactive carbonyl species (RCS) production, coupled with decreased antioxidant defense mechanisms, results in significant mitochondrial and endothelial cell damage resulting in apoptosis [19]. This oxidative stress disrupts the myocardium’s force-generating capacity, due to a lack of energy generation by the mitochondria (mitochondrial dysfunction), ultimately, affecting the normal contraction mechanism of the myocardium [20, 21]. Moreover, disruptions in cytoskeletal proteins, such as titin, contribute to myofibrillar disarray and defects in ion channel function contribute to the progressive loss of cardiomyocyte integrity and function [18, 22]. These changes are crucial in understanding the pathophysiology of cardiomyopathy. In terms of genetics, sarcomere mutations play a significant role. It is estimated that 40–60% of cases of hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM) have a genetic cause. The mutations associated with these cardiomyopathies often pertain to the regulation of cardiomyocyte contractility. HCM is specifically characterized by pathological left ventricular hypertrophy, myofibril disarrays, and a decrease in myofibril density. These abnormalities lead to a loss of force in isolated cardiomyocytes [23]. Interestingly, patients with HCM may exhibit a higher ejection fraction, not due to increased contractility but rather due to a decrease in ventricular cavity capacity. Conversely, DCM is characterized by a thin and dilated ventricular wall with systolic dysfunction [6]. A mutation in lamin A/C has been linked to the force production in cardiac cells in DCM [24]. The ventricular cavity’s volume in DCM patients is substantially larger compared to that in HCM patients, contributing to a significantly lower ejection fraction. The comprehensive flow diagram in Figure 2 illustrates the intricate cellular and molecular mechanisms underlying the different stages in the development of cardiomyopathy in response to various risk factors, either alone or in combination, resulting in the generation of several intracellular mediators, such as ROS, RCS, inflammation, endothelial and mitochondrial dysfunction, generation of transforming growth factor beta (TGF-β), fibrosis, apoptosis, cardiac remodeling, and subsequent damage to calcium transporting and contractile proteins, all resulting in impaired cardiac muscle contraction and subsequently, cardiomyopathy and possible sudden cardiac death. This diagram serves as a visual representation of the multifaceted processes involved in the pathogenesis of cardiomyopathy.

Figure 2.

Flow diagram illustrating the cellular and molecular mechanisms of the development of cardiomyopathy due to insult from risk factors. ROS: reactive oxygen species; ROS = reactive carbonyl species; MDV = mitochondrial-derived vesicles; TGF-β = transforming growth factor beta; Ca²⁺ = calcium; Na⁺ = sodium; K⁺ = potassium (drawn by hand).

5. Types of cardiomyopathies, diagnosis, treatment, and specific management

The flow diagram in Figure 3 illustrates the different subtypes of known cardiomyopathies to affect patients and they include DCM, HCM, RCM, ARVC and to a lesser extent, left ventricular non-compaction (LVCN) and Takotsubo cardiomyopathy (TCM). The review will now discuss the six types of cardiomyopathies in relation to pathophysiology, treatment, and prevention, but with more emphasis on the first four.

Figure 3.

Flow diagram illustrating the different types of known cardiomyopathies to affect patients (drawn by hand).

5.1 Dilated cardiomyopathy (DCM)

DCM is characterized by the gradual expansion of the ventricles of the heart, reduced ability to contract, and inadequate filling of the ventricles. The etiology of this condition is complex and arises from a combination of genetic, environmental, and behavioral factors. The complex etiology of DCM is influenced by genetic alterations, viral infections, exposure to toxins, persistent alcohol consumption, autoimmune illnesses, and other risk factors, including hypertension, obesity, and diabetes [6, 25]. DCM is marked by the progressive enlargement of the ventricles of the heart, accompanied with reduced ability to contract to eject blood, and inadequate relaxation delaying filling of the ventricles. The etiology of this condition is complex and arises from a combination of genetic, environmental, and lifestyle factors [26]. The complex etiology of DCM is influenced by genetic alterations, viral infections, exposure to toxins, persistent alcohol consumption, autoimmune illnesses, and other risk factors, including hypertension, obesity, and diabetes [6, 27].

The pathogenesis of DCM at the subcellular, cellular, and molecular levels includes a variety of structural and functional problems within the myocardium. Myocardial hypertrophy, myofibrillar and mitochondrial disarray including reduced dimensions, apoptosis, fibrosis, and derangements in myocyte calcium and contractile proteins are examples of these [17]. These cellular abnormalities result in reduced contractility and relaxation of the cardiac muscle, leading to decreased pumping capacity and, eventually, heart failure (see Figure 2). Furthermore, changes in calcium processing within cardiomyocytes play an important role in contractile failure [18, 22, 28]. Calcium ion dynamics that are out of balance affect normal contraction and relaxation rhythms, further reducing cardiac output. On the molecular level, the pathogenesis of DCM involves complex changes in cardiomyocyte gene expression patterns. These alterations cause disruptions in several signaling pathways that are critical for regular heart function. Among these include anomalies in calcium signaling, β-adrenergic signaling, and stimulation of the renin-angiotensin-aldosterone system (RAAS) [29, 30].

Concurrently, increased reactive oxygen and carbonyl species formation in DCM cause oxidative stress, producing cellular damage and aggravating ventricular contractility dysfunction [19]. A thorough understanding of these molecular pathways is critical for identifying potential therapeutic targets that offer promise for more effective management of this severe disorder [31]. The complex signaling pathways involved in DCM pathophysiology play critical roles in the disease’s genesis and progression. Renin-angiotensin-aldosterone system (RAAS) activation is a well-known event in DCM, contributing to cardiac remodeling, fibrosis, and myocardial failure [32]. Another important factor in DCM is dysregulation of β-adrenergic receptors and their related signaling pathways, which results in abnormalities in cardiac function, including contractility and relaxation [30]. Calcium signaling, a critical component of heart function, is severely disrupted in DCM [18]. Calcium homeostasis disruptions inside cardiac cells highlight the development of cardiomyocyte failure, promoting disease progression. A more comprehensive understanding of the functions that these signaling pathways play not only provides insight into the etiology of DCM, but also opens the door to potential treatment strategies [18, 33].

Chronic stress on the heart causes remodeling that includes changes to the molecular, cellular, and extracellular matrix. This remodeling causes changes in the structure, size, and function of the heart, such as ventricular dilatation, decreased contractile function, and increased stiffness [17]. Myocardial remodeling contributes considerably to the development and progression of DCM by inducing cardiac fibrosis, hypertrophy, inflammation, and apoptosis, all of which result in reduced cardiac function and poorer clinical outcomes [17, 34]. The consequences of decreased cardiac output in DCM are systemic, impacting various organs and systems throughout the body. Because the heart’s ability to adequately pump blood is impaired, tissue perfusion is reduced, resulting in severe symptoms, such as weariness, weakness, and exercise intolerance. DCM is characterized by pulmonary congestion and oedema, which result from fluid accumulation in the lungs caused by increased pulmonary capillary pressure. Hepatic and renal dysfunctions may occur in severe cases of DCM, as diminished cardiac output limits blood supply to these essential organs, resulting in organ damage [35].

5.2 Diagnosis of DCM

DCM diagnosis is a sophisticated procedure that relies on a thorough examination of clinical symptoms, diagnostic tests, and the meticulous exclusion of other probable causes of heart failure. DCM is characterized clinically by symptoms, such as dyspnoea, tiredness, lower limb oedema, and the presence of an enlarged heart on physical examination. To examine heart function, size, and structural abnormalities, a battery of imaging techniques, including echocardiogram (ECG), cardiac magnetic resonance imaging (MRI), and cardiac computed tomography (CT) scans, are used. Additional laboratory tests, including tests such as as blood analysis and genetic profiles, may also be used to improve diagnostic accuracy. DCM must be distinguished from other cardiomyopathies and cardiac pathologies, such as hypertrophic cardiomyopathy, restrictive cardiomyopathy, ARVC, and ischemic heart disease, with great care [36].

5.3 Treatment of DCM

The treatment of DCM aims to slow disease development, control symptom loads, and improve overall survival. Angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), beta-blockers, and diuretics are key medications for improving heart function and alleviating symptoms. Devices, such as implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization treatment (CRT), are used in more severe situations to battle arrhythmias and optimize heart function. Heart transplantation emerges as the ultimate option for individuals suffering from end-stage dilated cardiomyopathy who have failed to respond to conventional therapy approaches. The comprehensive care of dilated cardiomyopathy is a complex endeavor that frequently necessitates a multidisciplinary approach that combines medicinal interventions with device-based therapies to improve patient outcomes [37]. While there are recognized therapy techniques such as pharmacological drugs, medical technologies, and heart transplantation, a comprehensive understanding of the disease’s pathophysiology is a prerequisite for developing more effective therapeutic strategies. Ongoing research efforts to understand the molecular processes underlying DCM development and identify novel treatment targets have the potential to significantly improve patient outcomes and refine the comprehensive management of this devastating disorder.

5.4 Hypertrophic cardiomyopathy (HCM)

HCM is the most frequent hereditary cardiovascular illness. The condition is caused by mutations in genes that encode cardiac sarcomere protein, resulting in a wide range of phenotypic expressions and clinical outcomes [38]. HCM causes excessive left ventricular (LV) growth (hypertrophy), affecting blood flow [39]. Obstructive HCM is distinguished by a thicker septum that blocks the LV outflow pathway during systole [40]. This obstruction raises intraventricular pressure, lowering cardiac output and causing a cascade of chest discomfort, shortness of breath, and syncope [38]. Non-obstructive HCM has a stiff LV wall, but no major outflow tract blockage. However, this compromises diastolic filling, decreasing cardiac output and producing tiredness, exercise intolerance, and potentially heart failure [39]. Furthermore, myocardial ischemia due to reduced blood supply to the thickened heart muscle can cause chest pain during exercise [38]. Moreover, uncommon, HCM can contribute to this sudden cardiac death in young athletes due to either arrhythmias or LV outflow tract obstruction [38].

5.5 Diagnosis and treatment of HCM

An echocardiogram is normally employed to diagnose hypertrophic cardiomyopathy. The test uses sound waves (ultrasound) to ascertain if the muscle of the heart is enlarged or usually thick. The test also helps to illustrate how well the chambers and valves of the heart are functioning. Other supporting clinical diagnostic tests involve MRI scan (creating analytic images of the heart) and echocardiogram (ECG), especially during exercise stress test to determine irregular heart rhythms and signs of heart thickening [36]. Beta-blockers can be used to lower the heart rate and diminish contractility, relieving chest discomfort and reducing outflow tract blockage [38]. Calcium channel blockers increase diastolic filling in non-obstructive HCM [39]. However, disopyramide directly lowers outflow tract obstruction in obstructive HCM [38]. In extreme situations, surgical myectomy eliminates extra muscle from the septum, enhancing LV performance and easing outflow tract obstruction [38]. Also, lifestyle changes, such as avoiding intense activity, reducing stress, and keeping a healthy weight, are critical for symptom management and long-term well-being [39].

5.6 Restrictive cardiomyopathy (RCM)

RCM is a rare complex subtype of cardiomyopathy characterized by increased myocardial stiffness, which results in poor ventricular filling during diastole and consequent cardiac failure. Unlike other types of cardiomyopathies, which predominantly impact heart contractility, RCM primarily affects the heart’s capacity to relax and adequately fill with blood, resulting in decreased cardiac output and the presentation of heart failure symptoms [38]. RCM pathophysiology is essentially characterized by aberrant stiffness and reduced compliance of myocardial tissue. This stiffness can be caused by one of the two things: aberrant substances infiltrating the heart muscle or genetic abnormalities that result in the deposition of abnormal proteins within the myocardium. These structural changes impair normal myocardial architecture and obstruct the heart’s relaxation and expansion during diastole, a critical phase for ventricular filling. As a result of RCM, ventricular filling is disturbed, and preload is lowered [41]. Diverse substances, such as amyloid proteins, fibrous tissue, or aberrant mineral deposits like iron, invade the myocardium in infiltrative variants of RCM. These infiltrates alter the normal structure of the myocardium, resulting in increased myocardial stiffness. Genetic variants of RCM, on the other hand, require mutations in specific genes, which are frequently responsible for encoding sarcomere or cytoskeletal proteins. These mutations cause aberrant protein buildup within the heart, worsening cardiac compliance difficulties [42]. RCM causes increased myocardial stiffness, which causes raised filling pressures within the heart chambers, notably in the atria. As a result, the atria widen to handle the higher pressure and compensate for the poor ventricular filling. This compensatory mechanism, however, may eventually fail, resulting in the onset of heart failure symptoms, such as dyspnoea, tiredness, oedema, and exercise intolerance [39].

5.7 Diagnosis and treatment of RCM

Because of the variety of clinical manifestations and the necessity to separate it from other cardiomyopathies, diagnosing restrictive cardiomyopathy can be difficult. A full clinical assessment, echocardiography, cardiac MRI, and occasionally cardiac biopsy, are used to determine the underlying reason and confirm the diagnosis [40]. RCM management is primarily focused on treating the underlying cause wherever possible. Treatment for infiltrative disorders focuses mostly on managing the underlying condition (e.g., amyloidosis therapy) [43]. Because genetic alterations are typically permanent, the emphasis in genetic RCM often switches to symptom treatment and the prevention of consequences. To relieve symptoms associated with congestion and fluid retention, medications such as diuretics may be administered. Furthermore, the treatment of atrial fibrillation, a prevalent arrhythmia in RCM, and the optimization of heart rate regulation are critical in symptom management [44].

5.8 ARVC

This type of cardiomyopathy is due mainly to the infiltration of fatty materials in the right ventricular free wall of the myocardium. This pathological process arises from the mutation of genes and can cause sudden cardiac death, especially in young people and athletes. This disease is believed to be associated with strenuous exercise and it was first identified and described by Fontaine [45] and is associated with the sudden development of ventricular tachycardia with the left bundle branch pattern [46]. It is believed that 1 in 2500–5000 is affected, accounting for 7–10% of sudden unexplained death in an individual less than 65 years of age. It is very prevalent in young adults and male-to-female ratio of 2.7 to 1 [47, 48]. The precise pathophysiology of ARVC is still unknown, but it is believed to involve apoptosis of cardiomyocytes. Recent studies have identified the Sino-atrial pacemaker channel hyperpolarization activated cyclic nucleotide-gated potassium as the culprit in the pathophysiology of ARVC [49, 50]. It is believed that the disease process initiates in the subepicardial region of the heart, and it then extends to the endocardial region and then spreads transmurally around the myocardium. Some of the symptoms of this cardiac disease are palpitation fatigue, inflammation, syncope, and spontaneous cardiac arrest during strenuous physical activities.

5.9 Diagnosis and treatment of ARVC

Patients are normally diagnosed employing the history of the patient, electrocardiogram, echocardiograph, magnetic resonance imaging (MRI), and endocardial biopsy. The goal of management and treatment of ARVC is to prevent and decrease the number of sudden deaths employing pharmacological agents, and other clinical procedures, such as surgical (cardiac transplant), catheter ablation (to treat incessant tachycardia), and placement of an implantable cardioverter-defibrillator (to prevent sudden cardiac death of the patient) [6, 11].

5.10 Left ventricular non-compaction (LVNC) and Takotsubo cardiomyopathy (TCM)

Left ventricular non-compaction (LVNC) is an unusual, rare type of cardiomyopathy in left ventricular muscle of the heart. In this rare case, the left ventricle muscle develops into two structural forms as smooth and loose, like a thick web. In turn, the loose muscle tends to extend into the left ventricle resulting in weakness of the cardiac ventricular muscle and thereby, preventing the heart from pumping an adequate volume of blood around the body to meet constant demand. LVNC is diagnosed based on several clinical parameters, including cardiac testing with echocardiography, family history, medical history, and physical examination. Diagnosed patients are treated with either an implantable cardioverter-defibrillator (ICD) or a pacemaker (cardiac resynchronization therapy). On the other hand, TCM or broken heart syndrome is also another rare condition that can develop over time due to extreme stress, which results in the heart muscle unable to work efficiently as a pump. TCM occurs in both men, but more so in menopausal women. TCM is diagnosed by chest X-ray, blood biomarkers and tests, cardiac echocardiogram, coronary angiograph or cardiac catheterization and electrocardiogram (ECG test). TCM is treated with several drugs, including ACE inhibitor, beta-blockers, anticoagulants, intravenous fluids, oxygen therapy, and psychotherapy [6, 11].

6. General comments on cardiomyopathy including treatments, management, and prevention strategies

Comprehensive management and prevention of cardiomyopathy involve a multifaceted approach that includes both non-pharmacological and pharmacological strategies, as well as device-based interventions and surgical options when necessary. Cardiomyopathy pathophysiology includes a wide range of causes, demanding customized diagnostic and therapeutic strategies. A better understanding of the underlying mechanisms, as well as a multidisciplinary approach to patient therapy, is essential for properly managing this complex and complicated cardiac disorder. Figure 3 summarizes the main three forms of treatment of cardiomyopathy, including pharmacological, devices, and surgery. Accurate diagnosis of cardiomyopathy hinges on a multidimensional approach. A comprehensive medical history, family history, and physical examination provide initial insights. Advanced imaging techniques, including echocardiography, cardiac MRI, and nuclear imaging, offer critical structural and functional data. Genetic testing plays a pivotal role in identifying familial cardiomyopathy forms. In select cases, endomyocardial biopsy confirms diagnosis and guides therapeutic decisions [42].

In terms of medical management of cardiomyopathy, Figure 4 summarizes pharmacological, devices, and surgical intervention, used to manage cardiomyopathy. Pharmacological therapies are tailored to the type of cardiomyopathy and may include antihypertensives, blood thinners, anti-arrhythmic, and cholesterol-lowering medications to address various aspects, such as blood pressure, clot formation, heart rhythm abnormalities, and dyslipidemia [51, 52, 53, 54]. Additional treatments might involve aldosterone antagonists and corticosteroids to manage fluid retention and inflammation, respectively [12, 55].

Figure 4.

Diagram illustrating the pharmacological, devices, and surgical intervention, to treat cardiomyopathy (drawn by hand).

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For those where medication is insufficient, device-based interventions, such as pacemakers, implantable cardioverter-defibrillators, cardiac resynchronization therapy systems (CRTS), and left ventricular-assist devices (VADs), may be necessary to manage rhythm disorders to improve cardiac output [56, 57, 58, 59]. In severe or advanced cases, surgical interventions like septal myectomy or heart transplants become options to consider [60, 61]. Less invasive surgeries like alcohol septal ablation and catheter ablation are also employed for specific complications [62, 63]. These approaches collectively aim to slow disease progression, alleviate symptoms, reduce complications, and improve patient survival and quality of life.

7. Genes and cardiomyopathy

Both DCM and HCM are genetic disorders which can lead to heart failure, life-threatening arrhythmia, and subsequently sudden cardiac death (see Figure 2) and in these cases, the patients may require either heart transplantation or cardiac device implantation [64, 65]. These cardiomyopathies have prevalence rates of approximately 0.004% and 0.2%, respectively, with familial or genetic-related cases accounting for 20–50% of all cases [64, 65, 66, 67]. There are more than 50 genes that are associated with the development of these cardiomyopathies, with some ethnic-specific founder mutations in different parts of the world [68, 69]. Moreover, it has been reported that racial differences can affect mutational profiles with the genetic basis of these disorders different from one ethnic group to another among patients and with some patients with cardiomyopathies showing diverse clinical phenotypes [64], In addition, it has been reported that the phenotypes may correspond to specific genotypes. One typical example is that LMNA mutations in DCM patients are linked to a high incidence of sudden cardiac death [70, 71]. Current genetic evidence has indicated that the identification of the genotypes involved in prognosis and treatment response of patients with cardiomyopathy may contribute to risk stratification and accurate treatment decisions by the clinicians. However, further research is warranted in this novel area of study on cardiomyopathy in relation to its development and therapy.

8. Prevention and treatment of cardiomyopathy

Genetic or inherited types of cardiomyopathies are very difficult to prevent but, changes or adopting in lifestyle, including daily moderate exercise, and diet modifications play significant and measurable roles that prevent the development and even progression of cardiomyopathy and they may even cure the disease. The susceptible patient must focus on a nutritious diet low in sodium, fats, and carbohydrates, but high in fruits, fibers, vegetables, and whole grains, foods which are rich in oxidants to manage blood pressure and weight [55]. The American Heart Association (AHA) underscores the importance of a low-fat and low-salt diet for heart health [72]. Regular physical activity, as recommended by the Physical Activity Guidelines for Americans [65], plays a vital role, with a suggestion of at least 150 minutes of moderate aerobic exercise weekly to maintain cardiovascular health. Achieving and maintaining a healthy weight range is crucial as is ensuring adequate sleep and reducing stress. Abstinence from alcohol and tobacco is also advised to minimize cardiac stress [65, 72]. The flow diagram in Figure 5 illustrates several natural ways whereby people can help themselves to both reduce and prevent the development of cardiomyopathy. They must avoid obesity, control their diabetes or avoiding it, reducing salt, alcohol drinking, smoking habits, and stress levels, monitor their weight and blood pressure regularly, practising yoga and meditation and seek psychological intervention to adhere to daily drug intakes and lifestyle changes [67, 69, 71]. Together, these proposed cost-effective interventions can lead to longevity and a better quality of life.

Figure 5.

Diagram illustrating several natural ways whereby people can help themselves to both reduce and prevent the development of cardiomyopathy leading to longevity and a better quality of life (drawn by hand).

9. Conclusion

In conclusion, the comprehensive review of cardiomyopathies presented here sheds light on the intricate nature of these cardiac disorders. Cardiomyopathies are a diverse group of conditions affecting both adults and children worldwide, regardless of common cardiovascular comorbidities. The epidemiological data underscore the substantial public health concern, with a prevalence of approximately 1 in 500 adults and an incidence of about 12 cases per million in children. Understanding the risk factors associated with cardiomyopathy is crucial for early identification and prevention. Genetic mutations, family history, viral infections, lifestyle factors, and comorbid conditions contribute to the complexity of the disease, emphasizing the need for personalized management strategies. The review categorizes cardiomyopathies into distinct types, each with its own set of characteristics, which further highlight the complexity of the condition. The subcellular, cellular, and molecular mechanisms underlying cardiomyopathy development elucidate the intricate pathophysiology, providing a foundation for targeted therapeutic interventions and ongoing research. Clinical presentation varies, but based on type and severity, an early and accurate diagnosis is essential for effective management. A combination of diagnostic approaches, including medical history, physical examination, and various imaging and genetic tests, aids in this process. Prevention strategies encompass lifestyle modifications and genetic counseling, emphasizing the importance of healthy habits and managing underlying risk factors. The treatment spectrum includes medications, device implantation, lifestyle changes, and surgical interventions, all tailored to the specific needs of each patient. Emerging therapies like gene therapy hold promise for more targeted approaches. The review also offers healthcare professionals and researchers the knowledge needed to enhance patient care and alleviate the global burden of this intricate cardiac condition. Continued research and advancements in diagnosis and treatment hold hope for improved outcomes for individuals affected by cardiomyopathy.