Title: Valvular heart disease
Content:  Tricuspid regurgitation is usually secondary to right ventricular dilation which may be due to left ventricular failure (the most common cause), right ventricular infarction, inferior myocardial infarction, or cor pulmonale Other causes of tricuspid regurgitation include carcinoid syndrome and myxomatous degeneration.
Title: Right ventricular hypertrophy
Content:  RVH usually occurs due to chronic lung disease or structural defects in the heart. One of the most common causes of RVH is pulmonary hypertension (PH), defined as increased blood pressure in the vessels supplying blood to the lungs. PH leads to increased pulmonary artery pressure. The right ventricle tries to compensate for this increased pressure by changing its shape and size. Hypertrophy of individual myocytes results in an increase in right ventricular wall thickness. The worldwide incidence of PH is 4 per million people. RVH occurs in approximately 30% of these cases. PH is broadly split into five categories by the World Health Organization, based on the underlying cause. The incidence of RVH varies between the groups. Common causes of PH include chronic obstructive pulmonary disease (COPD), pulmonary embolism, and other 
Title: Right ventricular hypertrophy
Content:  Right ventricular hypertrophy (RVH) is a condition defined by an abnormal enlargement of the cardiac muscle surrounding the right ventricle. The right ventricle is one of the four chambers of the heart. It is located towards the lower-end of the heart and it receives blood from the right atrium and pumps blood into the lungs. Since RVH is an enlargement of muscle it arises when the muscle is required to work harder. Therefore, the main causes of RVH are pathologies of systems related to the right ventricle such as the pulmonary artery, the tricuspid valve or the airways. RVH can be benign and have little impact on day-to-day life or it can lead to conditions such as heart failure, which has a poor prognosis.
Title: Heart failure
Content:  night. A limited ability to exercise is also a common feature. Chest pain, including angina, does not typically occur due to heart failure. Common causes of heart failure include coronary artery disease, including a previous myocardial infarction (heart attack), high blood pressure, atrial fibrillation, valvular heart disease, excess alcohol use, infection, and cardiomyopathy of an unknown cause. These cause heart failure by changing either the structure or the function of the heart. The two types of left ventricular heart failure – heart failure with reduced ejection fraction (HFrEF), and heart failure with preserved ejection fraction (HFpEF) – are based on whether 
Title: Right bundle branch block
Content:  Common causes include: normal variation, right ventricular hypertrophy or strain, congenital heart disease such as atrial septal defect, and ischemic heart disease. In addition, a right bundle branch block may also result from Brugada syndrome, pulmonary embolism, rheumatic heart disease, myocarditis, cardiomyopathy, or hypertension.{[cn}}
Title: Right-to-left shunt
Content: 1) Pulmonary stenosis (narrowing of the pulmonary valve and outflow tract, obstructing blood flow from the right ventricle to the pulmonary artery) ; 2) Overriding aorta (aortic valve is enlarged and appears to arise from both the left and right ventricles instead of the left ventricle, as occurs in normal hearts) ; 3) Right ventricular hypertrophy (thickening of the muscular walls of the right ventricle, this is a result of the increased amount of work the heart has to do) ; 4) Ventricular septal defect (a hole exists in the septum that divides the left and right ventricles) The most common cause of right-to-left shunt is the Tetralogy of Fallot, a congenital cardiac anomaly characterized by four co-existing heart defects.
Title: Tricuspid regurgitation
Content:  The causes of TR may be classified as congenital or acquired; another classification divides the causes into primary or secondary. Congenital abnormalities are much less common than acquired. The most common acquired TR is due to right ventricular dilatation. Such dilatation is most often due left heart failure or pulmonary hypertension. Other causes of right ventricular dilatation include right ventricular infarction, inferior myocardial infarction, and cor pulmonale. In regards to primary and secondary causes they are: • Primary causes • * Rheumatic • * Myxomatous • * Ebstein anomaly • * Endomyocardial fibrosis • * Endocarditis • * Traumatic (blunt chest injury) • Secondary causes • * Left ventricular systolic dysfunction • * Mitral valve stenosis or regurgitation • * Chronic lung disease • * Pulmonary thromboembolism • * Myocardial disease • * Right ventricular ischemia and infraction • * Left to right shunt • * Carcinoid heart disease
Title: Right ventricular hypertrophy
Content:  lung diseases. RVH often occurs as a result of these disorders. RVH is seen in 76% of patients with advanced COPD and 50% of patients with restrictive lung disease. RVH also occurs in response to structural defects in the heart. One common cause is tricuspid insufficiency. This is a disorder where the tricuspid valve fails to close properly, allowing backward flow of blood. Other structural defects which lead to RVH include tetralogy of Fallot, ventricular septal defects, pulmonary valve stenosis, and atrial septal defects. RVH is also associated with abdominal obesity, elevated fasting blood glucose, high systolic blood pressure, and fractional shortening of the left ventricular mid-wall. Other risk factors for RVH include smoking, sleep apnea, and strenuous activity. These increase the risk of heart and lung disease and hence RVH.
Title: Heart failure
Content:   Right-sided heart failure is often caused by pulmonary heart disease (cor pulmonale), which is typically caused by difficulties of the pulmonary circulation, such as pulmonary hypertension or pulmonic stenosis.Physical examination may reveal pitting peripheral edema, ascites, liver enlargement, and spleen enlargement. Jugular venous pressure is frequently assessed as a marker of fluid status, which can be accentuated by eliciting hepatojugular reflux. If the right ventricular pressure is increased, a parasternal heave may be present, signifying the compensatory increase in contraction strength. Backward failure of the right ventricle leads to congestion of systemic capillaries. This generates excess fluid accumulation in the body. This causes 
Title: Right heart strain
Content:  Right heart strain (also right ventricular strain or RV strain) is a medical finding of right ventricular dysfunction where the heart muscle of the right ventricle (RV) is deformed. Right heart strain can be caused by pulmonary hypertension, pulmonary embolism (or PE, which itself can cause pulmonary hypertension ), RV infarction (a heart attack affecting the RV), chronic lung disease (such as pulmonary fibrosis), pulmonic stenosis, bronchospasm, and pneumothorax. When using an echocardiograph (echo) to visualize the heart, strain can appear with the RV being enlarged and more round than typical. When normal, the RV is about half the size of the left ventricle (LV). When strained, it can be as large as or larger than the LV. An important potential finding with echo is McConnell's sign, where only the RV apex wall 

Question: what is the most common cause of right ventricular heart failure?
Answer: left-sided heart failure.
pulmonary heart disease.