ABSTRACT
ECG changes in rheumatic mitral stenosis (MS) are reflection of hemodynamic consequences of the left atrial outflow obstruction. Pressure overload of left atrium (LA) due to MS results in variable degree of LA enlargement, depending upon the severity and duration of the mitral valve disease. Associated mitral regurgitation may further increase the insult on left atrium. Variable degree of scarring and conduction abnormalities in the left atrium also exist because of hemodynamic insult and underlying rheumatic heart disease. Back pressure from left atrium results in pulmonary venous hypertension followed by pulmonary arterial hypertension. This results in right ventricular hypertrophy and later on right atrial enlargement. In many cases, accompanying tricuspid valve disease augments the right atrial abnormalities. Pressure and volume overload of atria results in various rhythm abnormalities ranging from atrial premature beats to atrial tachycardia, atrial flutter and atrial fibrillation (AF). Since mitral valve per se has no ECG contribution, there are little or no ECG abnormalities in hemodynamically insignificant MS. Presence of concomitant abnormalities of other valves will have variable effect on the ECG changes due to MS. Chest radiograph is the initial imaging tool in the evaluation of MS and is frequently diagnostic. Moreover, the radiographic findings also provide considerable insight into the severity of MS and are useful in documenting the progression of disease.
