Doctors classify heart failure, the condition that occurs when the heart fails to pump enough blood to meet the needs of the body, as either systolic heart failure, diastolic heart failure or a combination of both. Systole describes the phase of the heartbeat when the two lower chambers, the ventricles, contract to propel the blood. Between contractions the ventricles relax and expand, filling with blood, a phase known as diastole. Conditions that affect the ability of the heart muscle to stretch and expand between contractions cause diastolic heart failure.
High Blood Pressure
Blood pressure describes the pressure the blood exerts against the walls of the arteries. Doctors define high blood pressure, a condition known as hypertension, as a systolic reading of 140 mmHg or higher and a diastolic reading of 90 mmHg or higher, according to the University of Maryland Medical Center. High blood pressure not only damages the arteries but also causes the heart to pump more forcefully in order to expel the blood from the ventricles. Over time the added pressure on the heart muscle leads to hypertrophy, a condition characterized by the thickening of the heart wall. As the heart wall becomes stiffer, the ventricles cannot expand, leading to diastolic heart failure.
Constrictive Pericarditis
Constrictive pericarditis describes a specific type of pericarditis---a condition characterized by inflammation of the sac surrounding the heart. Constrictive pericarditis, a chronic condition, causes the formation of scar tissue on the heart muscle that result in the heart becoming thicker. As the heart muscle thickens it tightens restricting the heart from stretching and expanding to allow the ventricles to fill with blood. Constrictive pericarditis, a serious condition, usually develops due to inflammation caused by heart surgery, radiation therapy or tuberculosis, according to MedLine Plus and the National Institutes of Health.
Aortic Valve Stenosis
Oxygenated blood enters the heart through the pulmonary vein into the left atrium, the upper left chamber of the heart. As the heart contracts, blood travels through the mitral valve into the left ventricle. The left ventricle contracts to propel blood through the aortic valve into the aorta that carries the blood to the body. Aortic valve stenosis describes a condition in which the flaps, known as leaflets, fail to open properly. This restricts the flow of blood from the left ventricle to the aorta. The left ventricle compensates by contracting harder to push the blood through but over time this causes the left ventricle wall to thicken and the ventricle chamber to enlarge, leading to diastolic dysfunction. If left untreated, aortic valve stenosis can cause diastolic heart failure.
