Why might the apex beat be impalpable?
Sometimes apex beat is impalpable because of - Muscular of fat chest wall - Pleural effusion - Emphysema - Pneumothorax - Constrictive percarditis - Dextrocardia - Marked mediastinal shift - Reduced pulse as in Tamponade and Restrictive Pericarditis - Displacement of apex beat past the mid-axillary line due to excessive left ventricular hypertrophy (rare)