Better do an electrocardiogram. Obese people have high blood pressure and increased cardiac afterload. When lying flat, the amount of blood returning to the heart increases, which aggravates the preload of the heart. If this happens for a long time, myocardial hypertrophy and myocardial ischemia will occur. When the pressure in the heart rises, the pressure in the pulmonary circulation will be too high. When lying on your back, the amount of blood flowing back to your heart increases, which increases the burden on your heart. Myocardial ischemia is relatively aggravated and pulmonary congestion is also aggravated. Appear, chest tightness, cough, take some antihypertensive drugs, positive inotropic drugs, should be relieved.