The following major complications can occur in rheumatic heart valve disease: (1) congestive heart failure 50% of patients with rheumatic heart disease are prone to congestive heart failure. The erosion of perennial rheumatic inflammation, impaired myocardial contractile function, and overload of the heart, such as severe mitral stenosis during pregnancy, childbirth, strenuous physical activity, and infection, can cause an accelerated heart rate, resulting in shortened left ventricular diastole and increased left atrial pressure, leading to increased pulmonary capillary pressure and plasma leakage into the tissue spaces or alveoli, causing acute pulmonary edema. The patient may have severe paroxysmal dyspnea, cyanosis, coughing pink foamy sputum, and lungs full of rales, which is called congestive heart failure. (2) Arrhythmias The most common arrhythmias are premature atrial contractions, atrial fibrillation, and paroxysmal tachycardia. Among them, the incidence of atrial fibrillation can be as high as 40% to 50%. Atrial fibrillation is often preceded by frequent premature atrial beats, atrial flutter, or paroxysmal atrial fibrillation, and later develops into persistent atrial fibrillation. (3) Embolism Patients with mitral stenosis with atrial fibrillation are most likely to have infarction. Patients with mitral stenosis have a tendency to form thrombi if atrial fibrillation occurs because of blood stagnation due to dilatation of the left atrium and left ear. The fresh thrombus is easily dislodged and embolism occurs, which can cause embolism of the brain, kidney, mesentery, spleen, limb vessels, and coronary arteries. (4) Subacute infective endocarditis Patients with purely high stenosis are rarely complicated by infective endocarditis because of valve stiffness, thickening, and calcification, whereas patients with mild mitral stenosis combined with mitral valve or aortic valve insufficiency are prone to infective endocarditis. (5) Pulmonary Infections Patients with valvular lesions are prone to recurrent pulmonary infections due to increased left atrial pressure, pulmonary stasis, reduced pulmonary compliance, and interstitial edema, which can trigger and exacerbate heart failure when the body’s resistance is reduced. (6) Other Patients with severe mitral stenosis may have hoarseness due to compression of the regurgitant laryngeal nerve by the large left atrium or dysphagia due to compression of the esophagus.