Systolic Heart Failure: Causes, Symptoms, Diagnosis and Treatment

~Introduction

Heart failure is a growing global health challenge that affects millions of people worldwide. It occurs when the heart cannot pump enough blood to meet the body’s needs. There are two primary types of heart failure: systolic and diastolic.

Systolic heart failure, also known as heart failure with reduced ejection fraction (HFrEF), happens when the left ventricle of the heart loses its ability to contract effectively. This means the heart cannot pump out enough oxygen-rich blood to the body, leading to fatigue, shortness of breath, and fluid retention.

This article explores everything you need to know about systolic heart failure — from causes and pathophysiology to symptoms, diagnosis, and management strategies.

~What Is Systolic Heart Failure?

In a healthy heart, the left ventricle contracts forcefully during systole (the pumping phase), ejecting about 55–70% of the blood within it — a measurement known as the ejection fraction (EF).

In systolic heart failure, the heart muscle becomes weakened and dilated, reducing the ejection fraction to below 40%. As a result, less blood is pumped out with each heartbeat, and the body receives less oxygen and nutrients.

This inefficiency causes blood to back up in the lungs and veins, leading to congestion, shortness of breath, and swelling.

~Pathophysiology: How Systolic Heart Failure Develops

The underlying mechanism of systolic heart failure involves myocardial damage that impairs the heart’s ability to contract. This damage can result from various causes such as ischemic heart disease, hypertension, or viral infections.

1. Myocardial Injury and Remodeling

When heart muscle cells (myocytes) are injured — for example, after a heart attack — they lose their contractile ability. To compensate, the remaining healthy cells work harder, leading to hypertrophy (thickening) and dilation of the ventricles.

Over time, this process, known as ventricular remodeling, further weakens the heart, reducing its pumping efficiency.

2. Neurohormonal Activation

As cardiac output falls, the body triggers compensatory mechanisms:

The sympathetic nervous system releases adrenaline to increase heart rate.
The renin-angiotensin-aldosterone system (RAAS) retains sodium and water to boost blood volume.
Vasoconstriction occurs to maintain blood pressure.

While these mechanisms temporarily support circulation, chronic activation leads to fluid overload, increased afterload, and further cardiac damage.

3. Reduced Cardiac Output

Ultimately, the weakened ventricle cannot generate enough force to circulate blood effectively, leading to symptoms of congestive heart failure.

~Causes of Systolic Heart Failure

Systolic heart failure can result from several underlying conditions that damage or weaken the heart muscle.

1. Coronary Artery Disease (CAD)

The most common cause of systolic heart failure. Blocked coronary arteries reduce oxygen supply to the heart muscle, leading to ischemia and myocardial infarction (heart attack).

2. Hypertension (High Blood Pressure)

Chronic high blood pressure increases the workload on the left ventricle, causing it to thicken and eventually weaken.

3. Cardiomyopathy

Various forms of cardiomyopathy (dilated, viral, or alcoholic) can damage heart muscle tissue, impairing contraction.

4. Valvular Heart Diseases

Diseases such as aortic stenosis or aortic regurgitation force the heart to pump harder, leading to ventricular dilation and dysfunction.

5. Myocarditis

Inflammation of the heart muscle, often caused by viral infections, can lead to weakened contractions and systolic dysfunction.

6. Arrhythmias

Persistent irregular heartbeats like atrial fibrillation or ventricular tachycardia can reduce cardiac efficiency.

7. Toxins and Drugs

Long-term alcohol use, certain chemotherapy agents (e.g., doxorubicin), or drug abuse (e.g., cocaine) can cause direct cardiac injury.

8. Genetic Factors

Inherited forms of dilated cardiomyopathy can predispose individuals to systolic failure.

~Risk Factors

Common risk factors that increase the likelihood of developing systolic heart failure include:

Coronary artery disease
High blood pressure
Diabetes mellitus
Obesity
Smoking
Excessive alcohol consumption
Family history of heart failure
Sedentary lifestyle
Older age

~Symptoms of Systolic Heart Failure

The symptoms of systolic heart failure develop gradually and worsen over time. They result from the heart’s inability to pump blood effectively and the body’s response to this failure.

1. Shortness of Breath (Dyspnea)

Occurs first during exertion and later at rest due to fluid buildup in the lungs (pulmonary congestion).

2. Fatigue and Weakness

Decreased blood flow leads to muscle fatigue and reduced exercise tolerance.

3. Persistent Cough or Wheezing

Caused by pulmonary congestion and fluid accumulation.

4. Swelling (Edema)

Fluid retention leads to swelling in the feet, ankles, legs, and sometimes the abdomen.

5. Rapid or Irregular Heartbeat

The heart compensates for poor pumping by beating faster, but this often worsens the condition.

6. Weight Gain

A result of fluid buildup rather than fat increase.

7. Difficulty Sleeping Flat (Orthopnea)

Shortness of breath worsens when lying down, forcing patients to use multiple pillows at night.

8. Paroxysmal Nocturnal Dyspnea (PND)

Sudden nighttime episodes of breathlessness that wake the person up.

9. Decreased Urination During the Day and Increased Urination at Night

Due to altered kidney perfusion and fluid redistribution.

~Diagnosis of Systolic Heart Failure

Diagnosing systolic heart failure involves a combination of clinical evaluation, imaging, and laboratory testing.

1. Physical Examination

A doctor may note:

Enlarged heart (cardiomegaly)
Crackles or rales in lungs
Jugular venous distention
Swelling in legs or abdomen
Rapid heart rate or irregular rhythm

2. Diagnostic Tests

a. Echocardiogram

The gold standard for diagnosing systolic heart failure. It measures:

Ejection fraction (EF): Less than 40% confirms systolic failure.
Chamber size and wall motion abnormalities
Valve function

b. Electrocardiogram (ECG)

Reveals arrhythmias, myocardial infarction, or ventricular hypertrophy.

c. Chest X-Ray

Shows an enlarged heart and pulmonary congestion.

d. Blood Tests

BNP (B-type natriuretic peptide) or NT-proBNP — elevated in heart failure.
Kidney and liver function tests
Thyroid function tests

e. Cardiac MRI

Provides detailed imaging of heart structure and tissue composition.

f. Cardiac Catheterization

Assesses coronary artery blockages and measures intracardiac pressures.

~Treatment of Systolic Heart Failure

The main goals of treatment are to relieve symptoms, improve quality of life, prevent hospitalizations, and increase survival.

Management involves lifestyle changes, medications, and in severe cases, surgical interventions.

1. Lifestyle Modifications

Sodium restriction: Limit to <2 grams/day to reduce fluid retention.
Fluid restriction: Especially in advanced cases.
Regular exercise: Light-to-moderate aerobic activity improves endurance.
Weight monitoring: Daily weighing helps detect early fluid accumulation.
Avoid alcohol and smoking: These worsen heart damage.
Control blood pressure and diabetes: Prevents further cardiac deterioration.

2. Medications

a. ACE Inhibitors (e.g., Enalapril, Lisinopril)

Lower blood pressure, reduce afterload, and prevent remodeling.

b. ARBs (e.g., Losartan, Valsartan)

Used when ACE inhibitors are not tolerated.

c. ARNI (Angiotensin Receptor-Neprilysin Inhibitor)

Sacubitril/Valsartan improves survival and reduces hospitalizations.

d. Beta-Blockers (e.g., Metoprolol, Carvedilol)

Slow heart rate, improve ventricular function, and enhance long-term survival.

e. Aldosterone Antagonists (e.g., Spironolactone, Eplerenone)

Reduce fibrosis, fluid retention, and improve mortality rates.

f. Diuretics (e.g., Furosemide, Bumetanide)

Provide symptomatic relief from congestion and edema.

g. SGLT2 Inhibitors (e.g., Dapagliflozin, Empagliflozin)

Originally diabetes drugs, they have been shown to significantly improve heart failure outcomes.

h. Vasodilators (Hydralazine and Nitrates)

Used especially in patients intolerant to ACE inhibitors.

i. Digoxin

Enhances contractility and controls heart rate in certain patients.

3. Device-Based Therapies

a. Implantable Cardioverter-Defibrillator (ICD)

Prevents sudden cardiac death due to arrhythmias.

b. Cardiac Resynchronization Therapy (CRT)

Coordinates contraction between the heart’s ventricles to improve pumping efficiency.

c. Left Ventricular Assist Device (LVAD)

Mechanical pump that helps the heart pump blood in advanced cases.

4. Surgical Options

Coronary Artery Bypass Grafting (CABG): Restores blood flow in ischemic heart disease.
Heart Valve Repair or Replacement: For patients with valvular dysfunction.
Heart Transplantation: The last resort for end-stage systolic heart failure unresponsive to other treatments.

~Complications

If left untreated, systolic heart failure can cause several life-threatening complications:

Arrhythmias (Atrial fibrillation, Ventricular tachycardia)
Thromboembolism (Blood clots)
Kidney and liver dysfunction
Cardiogenic shock
Sudden cardiac death

~Prognosis

The prognosis of systolic heart failure depends on factors such as:

Age and overall health
Cause and severity of heart damage
Response to treatment
Presence of other conditions (diabetes, kidney disease)

With modern therapies, including ACE inhibitors, beta-blockers, and device-based interventions, the survival and quality of life of patients with systolic heart failure have significantly improved.

~Prevention

Preventing systolic heart failure focuses on reducing risk factors and maintaining heart health:

Manage blood pressure, cholesterol, and blood sugar levels
Follow a heart-healthy diet (low in saturated fats and salt)
Exercise regularly
Avoid smoking and excessive alcohol
Seek medical attention for chest pain or shortness of breath early
Treat heart diseases promptly

~Conclusion

Systolic heart failure is a serious, chronic condition that significantly impacts health and quality of life. However, with early diagnosis, lifestyle changes, and effective medical therapy, patients can manage their symptoms, reduce hospitalizations, and live longer, healthier lives.

Ongoing research and advances in treatment — such as ARNIs, SGLT2 inhibitors, and cardiac devices — continue to transform the outlook for those living with this condition.

Monday, October 20, 2025

Systolic Heart Failure: Causes, Risk Factors, Symptoms, Diagnosis, Treatment and Prevention