A 26-year-old woman, pregnancy I, 10 weeks of gestation, has been suffering from rheumatism since her childhood. With pregnancy her condition has deteriorated: her dyspnea increased, and she developed edema in her lower extremities. Her pulse is 86/min., the lips are cyanotic, there are systolic and diastolic murmurs over the cardiac apex. The liver protrudes 4 cm from under the costal margin. The woman was diagnosed with III degree heart failure, her left ventricular ejection fraction is less than 40%. What are the tactics of the patient management in this case?