Left ventricular

The principal manifestations of left ventricular failure are dyspnoea, cough crepitating at the bases of the lungs, enlargement of the heart due to hypertophy and dilation of the left ventricle, triple rhythm and pulses alternant. Dyspnea is usually the earliest manifestation of heart failure. It may occur on exertion or at rest. Dyspnoea at rest may be paroxysmal and is often nocturnal. Cheyne-Stokes respiration refers to a special from of periodic respiration which may or may not be accompanied by the sensation of dyspnoea. Dyspnoea at rest is always pathological. Dyspnoea on exertion occurs in normal people and hence must be assessed in relation to age, obesity and physical fitness. Progression or regression of dyspnoea on exertion is a valuable guide to the course of the underlying heart disease. Later dyspnoea will be present at rest and finally the patient cannot lie flat without distress (orthopnoea). In the recumbend posture the venous return to the heart is increased. Pulmonary congestion is aggravated and this together will the elevation of the diaphragm which results from lying down reduces still further the vital capacity of the lungs.