Heart Failure (Shah, 2020) – Is congestive heart failure genetic?

human heart photo

Nebula Genomics DNA Report for Congestive Heart Failure

Is congestive heart failure genetic? We created a DNA report based on a study that attempted to answer this question. Below you can see a SAMPLE DNA report. To get your personalized DNA report, purchase our Whole Genome Sequencing!

A sample report on congestive heart failure from Nebula Genomics
A sample report on congestive heart failure genetic variants from Nebula Genomics

Additional Information

What is Congestive Heart Failure? (Part 1 of Is congestive heart failure genetic?)

Congestive heart failure, or simply heart failure, is the inability of the heart to pump enough blood to meet the body’s requirements. The “pump weakness” or “weakened heart” manifests itself in reduced physical and mental performance. Additionally, when the left side of the heart is weak, water accumulates in the lungs, which manifests itself as shortness of breath, especially when the patient is lying down, and in severe cases, limits oxygen uptake in a life-threatening manner.

Congestive heart failure is the common result of many heart diseases, with long-standing high blood pressure and atherosclerotic narrowing of the vessels supplying the heart (i.e. coronary heart disease and expired heart attacks) being the most common causes. In therapy, in addition to the treatment and elimination of underlying diseases and risk factors, certain antihypertensive drugs play a major role, as they have been shown to prolong survival. 

Congestive heart disease during a heart attack
Congestive heart disease may be the result after a heart attack. Wikipedia. CC-Attribution-Share Alike 4.0 International.

Advanced heart failure often shows a relapsing course with recurrent decompensations, in which the affected person stores too much water and thus also “overloads” their heart. Cardiac decompensation is a common reason for hospitalization. It can often be managed with diuretic medications and intensive care if necessary, but it can also lead to death from relative health. Heart failure is a common disease with high mortality and, accordingly, is one of the leading causes of death.

Classification (Part 2 of Is congestive heart failure genetic?)

The types of heart failure are subdivided according to its course (acute or chronic), to the affected half of the heart (right or left, otherwise global), and to the mechanism.

Course

The two types of congestive heart failure based on course are acute heart failure and chronic heart failure.

Acute heart failure develops over the course of hours to days. Causes include:

  • Tachycardic (heart rate too high) or bradycardic (heart rate too low) cardiac arrhythmias
  • Sudden loss of pumping function due to a heart attack
  • Pulmonary embolism
  • Acute and severe inflammation of the heart muscle
  • Mechanical obstruction of ventricular filling, e.g. due to pericardial tamponade
  • Sudden valve insufficiency due to rupture of a pre-damaged heart valve

On the other hand, chronic heart failure develops over the course of months to years. 

It is characterized by faster heartbeat, thickening of the heart muscle, constriction of blood vessels, increase in blood volume, etc., which can compensate for the reduced pumping capacity of the heart. Compensated heart failure may show no symptoms or show symptoms only with physical exertion. In the decompensated stage, pathological water retention (edema) and shortness of breath (dyspnea) occur. This already occurs at rest or under low exertion.

Affected half of heart

Heart failure often does not affect both halves of the heart equally. Left side heart failure is characterized by blood backing up into the pulmonary vessels (often resulting in pulmonary hypertension) with coughing and shortness of breath, and even pulmonary edema. The impaired pumping capacity of the left ventricle also leads to decreased exercise capacity and eventually low blood pressure.

In right heart failure, the contraction failure of the right ventricle and right atrium, blood to the body backs up into the veins. The increased venous pressure can cause water retention in the tissues with edema, especially of the lower parts of the body (legs), as well as in the abdomen (ascites) and pleural cavity (pleural effusion).

Global heart failure with contraction insufficiency of the right and left ventricles shows symptoms of both left and right heart failure.

Mechanism

Functionally, a distinction can be made between forward and reverse heart failure. In forward failure, adequate pressure cannot be built up in the arteries, whereas in reverse failure, blood backs up in the body and pulmonary veins.

The symptoms of heart failure can also occur when an increased demand for blood flow to the organs can no longer be met:

  • Anemia – because of poor oxygen-carrying capacity, cardiac output must increase to ensure adequate oxygen delivery to tissues.
  • Hyperthyroidism – the pumping capacity of the heart is strongly stimulated, but so is the metabolism and thus the blood flow to the tissues. The tachycardia, among other things, can lead to (relative) heart failure.
  • Arteriovenous fistula – due to a short-circuit connection between arteries and veins, part of the cardiac output is consumed without benefit.
  • Sepsis/SIRS – the dilatation of small vessels and endothelial barrier dysfunction associated with the release of inflammatory mediators requires a greatly increased ejection output of the heart to maintain arterial blood pressure.

The American Heart Association distinguishes 4 classes of congestive heart failure based on symptoms and 4 objectives based on pathological evidence. This system is called the the New York Heart Association (NYHA) Functional Classification. 

ClassPatient SymptomsClassObjective Assessment
INo limitation of physical activity. Ordinary physical activity does not cause undue fatigue, palpitation, dyspnea (shortness of breath)ANo objective evidence of cardiovascular disease. No symptoms and no limitation in ordinary physical activity
IISlight limitation of physical activity. Comfortable at rest. Ordinary physical activity results in fatigue, palpitation, dyspnea (shortness of breath)BObjective evidence of minimal cardiovascular disease. Mild symptoms and slight limitation during ordinary activity. Comfortable at rest
IIIMarked limitation of physical activity. Comfortable at rest. Less than ordinary activity causes fatigue, palpitation, or dyspneaCObjective evidence of moderately severe cardiovascular disease. Marked limitation in activity due to symptoms, even during less-than-ordinary activity. Comfortable only at rest
IVUnable to carry on any physical activity without discomfort. Symptoms of heart failure at rest. If any physical activity is undertaken, discomfort increasesDObjective evidence of severe cardiovascular disease. Severe limitations. Experiences symptoms even while at rest

Epidemiology (Part 3 of Is congestive heart failure genetic?)

According to the CDC in 2020, about 6.2 million adults in the United States have heart failure.  In 2018, heart failure was mentioned on 379,800 death certificates (13.4%).

Heart failure is more common in some areas of the United States than in others, with particular prevalence in the south central and south eastern states.

Symptoms (Part 4 of Is congestive heart failure genetic?)

The CDC lists several common symptoms of congestive heart failure:

  • Shortness of breath during daily activities
  • Having trouble breathing when lying down
  • Weight gain with swelling in the feet, legs, ankles, or stomach (from water retention)
  • Generally feeling tired or weak

Chest pain can also be common if the symptoms are caused by a heart attack, when blood flow to the heart is blocked, or by sudden cardiac arrest, when the heart has stopped unexpectedly. The latter is often a cause of sudden cardiac death.  

The most severe form of heart failure is cardiogenic shock, which usually presents with severe shortness of breath, clouding of consciousness, cold sweat, weak and rapid pulse, and cool hands and feet.

Congestive heart failure in combination with coronary heart disease
Congestive heart failure occurs with other diseases such as coronary artery disease, which leads to similar symptoms. Wikipedia. CC-Attribution-Share Alike 4.0 International.

Congestive heart failure rarely occurs alone. Rather, it is often associated with concomitant diseases, which, depending on the cause of the heart failure, may include congenital heart disease, coronary artery disease, hypertension, dyslipidemia or obesity. Atrial fibrillation can be both a consequence and a cause of heart failure. The frequency of concomitant diseases is related to the patient’s age, personal risk factors (e.g. smoking) and the severity of the heart failure itself. 

Causes (Part 5 of Is congestive heart failure genetic?)

Some physical causes of congestive heart failure include:

  • Impaired contractility or filling of the heart due to direct damage to the heart muscle, e.g. in coronary heart disease, after myocardial infarction or due to myocarditis
  • Increased pumping resistance, e.g. in the case of high blood pressure in the systemic circulation (arterial hypertension) or in the pulmonary circulation (pulmonary hypertension) or narrowed aortic valve
  • Increased stroke volume in the case of heart defects, e.g. leaking aortic valve
  • Too low a heart rate in bradycardia or too low a stroke volume in tachycardia, resulting in a decrease in cardiac output
  • Constriction of the heart due to fluid in the pericardium
  • Increased blood demand of the body in case of severe general disease
  • anemia
  • Obstructive sleep apnea syndrome (OSAS), especially in the case of right heart failure
  • Side effects of numerous medications
  • Excessive viscosity (viscosity, hemoconcentration) of the blood can decrease cardiac output.

Is congestive heart failure genetic?

While congestive heart failure itself doesn’t appear to be genetically influenced to a great extent, the risks for heart diseases are affected by genetics. 

Three of the most commonly inherited heart diseases are symptoms of familial hypertrophic cardiomyopathy, familial dilated cardiomyopathy, and familial hypercholesterolemia. All of these diseases may lead to heart failure. Other risk factors are disorders such as hypertension, diabetes, high cholesterol, and coronary artery disease and these illnesses tend to run in families. 

Diagnosis (Part 6 of Is congestive heart failure genetic?)

Diagnosis is made based on a physical examination, family history, and various other diagnostic tests. Having family members with heart disease increases your risk of having a similar heart condition. Your doctor will also check for the presence of personal risk factors, such as high blood pressure, coronary artery disease or diabetes.

Some of the addition tests are noted on Mayo Clinic and may include:

  • Blood tests that look for signs of diseases that can affect the heart
  • Chest X-ray to assess the condition of your lungs and heart. Your doctor can also use an X-ray to diagnose conditions other than heart failure that may explain your signs and symptoms
  • Electrocardiogram (ECG) to help diagnose abnormal heart rhythms and damage to your heart
  • Echocardiogram to help visualize the size and shape of your heart along with any abnormalities. Ejection fraction can also be measured with this test
  • Stress test to measure the health of your heart by how it responds to exertion
  • Cardiac computerized tomography (CT) scan to collect images of your heart and chest.
  • Magnetic resonance imaging (MRI) to also obtain images of your heart
  • Coronary angiogram to help identify spot blockages
  • Myocardial biopsy to diagnose certain types of heart muscle diseases that cause heart failure
A chest radiograph
A chest radiograph with signs of congestive heart failure. Wikipedia. CC1.0.

Treatment (Part 7 of Is congestive heart failure genetic?)

Although congestive heart failure is often a chronic disease, there are approaches to help mitigate symptoms and help patients live longer and healthier lives. The 3 most common ways to treat heart failure are lifestyle changes, medications, and surgical procedures.

Lifestyle changes

To treat congestive heart failure it’s often recommended that, if necessary, patients:

  • Quit smoking
  • Maintain or lose weight
  • Track daily fluid intake
  • Avoid or limit alcohol and caffeine
  • Eat a heart healthy diet
  • Be physically active
  • Manage stress
  • Keep track of symptoms
  • Monitor blood pressure
  • Get adequate rest
  • Seek support
  • Get vaccinated against the flu
  • Follow heart patient guidelines for sexual activity
  • Select clothing that does not restrict circulation

Medication

Congestive heart disease is a complicated disease and patients are almost always prescribed multiple medications to treat different symptoms or contributing factors. The combinations of these drugs prolong life, improve the heart’s function, and heighten quality of life. Some typical medications are:

  • Angiotensin-converting enzyme (ACE) inhibitors: vasodilators that widen blood vessels to lower blood pressure, improve blood flow and decrease the workload on the heart 
  • Angiotensin II receptor blockers: an alternative to ACE inhibitors that perform similar functions
  • Beta blockers: slows heart rate, reduces blood pressure, and limits or reverses some of the damage to your heart if you have systolic heart failure
  • Diuretics: make you urinate more frequently and keep fluid from collecting in your body
  • Aldosterone antagonists: diuretics that also raise the level of potassium in the blood
  • Inotropes: intravenous medications that improve heart pumping function and maintain blood pressure
  • Digoxin (Lanoxin): increases the strength of your heart muscle contractions. It also tends to slow the heartbeat

Surgical procedures

When the congestive heart failure is serious or when a condition would benefit from correction, devices and surgical procedures may be recommended. 

  • Implantable cardioverter defibrillator (ICD)
  • Cardiac Resynchronization Therapy (CRT)
  • Left ventricular assist device (LVAD) to help your heart pump blood
  • Heart transplantation
  • Percutaneous coronary intervention (PCI, also referred to as angioplasty)
  • Coronary artery bypass
  • Valve replacement

If you liked this article, you should check out our other posts in the Nebula Research Library!