Causes of Heart Failure
The causes of heart failure are diverse and often interconnected. Involving a variety of conditions that damage or weaken the heart muscle, reduce its efficiency, or place it under chronic stress. Understanding the causes of heart failure is essential not only for accurate diagnosis and effective treatment. However, this is also important for prevention and long-term disease management.
At the centre of most cases of heart failure is a structural or functional abnormality of the heart. These abnormalities can impair the heart’s ability to fill properly during diastole (diastolic dysfunction) or eject blood efficiently during systole (systolic dysfunction). The heart may become stiff, thickened, weakened, or dilated—each of which interferes with normal circulation and oxygen delivery throughout the body.
One of the most common causes of heart failure is coronary artery disease (CAD). This condition occurs when the coronary arteries, which supply the heart muscle with oxygen-rich blood, become narrowed or blocked due to atherosclerosis (plaque buildup). When blood flow to the heart is restricted, parts of the muscle may weaken, especially after a heart attack (myocardial infarction), where a section of the heart muscle dies. The resulting scar tissue impairs pumping capacity, making CAD a leading contributor to heart failure with reduced ejection fraction (HFrEF).
Hypertension (high blood pressure) is another significant cause. Over time, elevated pressure in the arteries forces the heart to work harder to circulate blood. This increased workload causes the heart muscle—especially the left ventricle—to thicken (left ventricular hypertrophy) and become stiff. Eventually, this rigidity interferes with the heart’s ability to relax and fill effectively, leading to heart failure with preserved ejection fraction (HFpEF). In both cases, prolonged high blood pressure can wear down the heart’s resilience and adaptability.
Causes of Heart Failure
Cardiomyopathies, which refer to diseases of the heart muscle itself, are also frequent culprits. These can be classified as:
Dilated cardiomyopathy, where the heart becomes enlarged and weakened.
Hypertrophic cardiomyopathy, involving abnormally thickened heart muscle, often genetic in origin.
Restrictive cardiomyopathy, where the heart muscle becomes stiff and less compliant, impairing filling.
Arrhythmogenic right ventricular cardiomyopathy, a rare genetic condition involving fibrous and fatty infiltration of the heart muscle.
These disorders can be inherited or acquired due to infections, autoimmune diseases, or prolonged exposure to toxins.
Causes of Heart Failure
Valvular heart disease also contributes to heart failure. When heart valves are damaged—whether through degenerative changes, congenital defects, infections like endocarditis, or rheumatic fever—they may not open or close properly. This can lead to volume overload (as in mitral or aortic regurgitation) or pressure overload (as in stenosis), eventually weakening the heart and disrupting its ability to maintain effective circulation.
Arrhythmias, such as atrial fibrillation or persistent tachycardia, may both cause and exacerbate heart failure. When the heart beats too quickly, irregularly, or inefficiently, it reduces the time available for the ventricles to fill and pump blood effectively. Over time, these rhythm disturbances can lead to structural changes and reduced cardiac output.
Metabolic disorders also play a crucial role. Diabetes mellitus doubles the risk of heart failure, not only because of its association with coronary artery disease and hypertension but also due to diabetic cardiomyopathy—a condition characterised by metabolic and structural alterations in the myocardium independent of other cardiovascular diseases.
Thyroid dysfunction can contribute to heart failure in both directions: hyperthyroidism increases the heart’s metabolic demands and can cause tachyarrhythmias, while hypothyroidism can slow the heart rate, increase peripheral resistance, and cause fluid retention.
Causes of Heart Failure
Infections, particularly viral myocarditis, can cause inflammation and direct injury to heart muscle, leading to acute or chronic heart failure. Parasitic infections such as Chagas disease are significant causes in certain parts of the world. Bacterial infections affecting the heart valves (endocarditis) can similarly impair cardiac function.
Exposure to toxins or drugs—such as excessive alcohol, certain chemotherapy agents (e.g., doxorubicin), recreational drugs (e.g., cocaine), and some illicit anabolic steroids—can damage cardiac muscle cells and precipitate heart failure. Alcoholic cardiomyopathy is a well-recognised example of toxic-induced heart failure that improves with cessation of drinking.
Congenital heart defects are another category. Structural abnormalities present from birth—such as septal defects, valve malformations, or single ventricle anomalies—can impair heart function early in life and increase long-term risk of heart failure, even following surgical correction.
In some cases, anaemia, severe lung disease, or chronic kidney disease can contribute to a condition called high-output heart failure. In these cases, the heart is not failing because it is weak or stiff, but because it cannot keep up with the body’s increased demands for blood flow. Treating the underlying condition can often resolve this type of heart failure.
Pregnancy-related conditions, such as peripartum cardiomyopathy, can also trigger heart failure. This rare disorder develops in the last month of pregnancy or within several months after delivery. Its cause is not fully understood but is believed to involve inflammation, hormonal changes, and vascular dysfunction.
Finally, genetic mutations—even in the absence of structural abnormalities—can predispose individuals to heart failure. Inherited channelopathies and mitochondrial diseases may disrupt the heart’s electrical or energy systems, contributing to the development of systolic or diastolic dysfunction over time.
Causes of Heart Failure
In summary, the causes of heart failure are varied and often cumulative. Multiple risk factors frequently act together—such as a person with hypertension and diabetes who suffers a heart attack and later develops heart failure. Identifying and addressing each contributing factor is crucial for comprehensive treatment and long-term disease control.
