Congenital heart surgery principles

A 15-month-old boy is brought to the pediatrician for immunizations and assessment. His parents report that he is eating well and produces several wet diapers every day. He is occasionally fussy, but overall a happy and curious child. The boy was born at 39 weeks gestation via spontaneous vaginal delivery. On physical examination his vital signs are stable. His weight and height are above the 85th percentile for his age and sex. On chest auscultation, the pediatrician detects a loud harsh holosystolic murmur over the left lower sternal border. The first and second heart sounds are normal. An echocardiogram confirms the diagnosis of the muscular ventricular septal defect without pulmonary hypertension. Which of the following is the best management strategy for this patient?

One week after an aortic valve replacement surgery, a 55-year-old man is brought to the emergency room 30 minutes after the onset of severe, sharp chest pain. He appears pale and dyspneic but is alert, oriented, and speaks in full sentences. His temperature is 38°C (100.4°F), pulse is 192/min and thready, respirations are 22/min, and blood pressure is 80/50 mm Hg. Faint rales can be heard in the lower lung fields on both sides on auscultation. There is a midline thoracotomy scar with mild reddening but without warmth or discharge. A portion of an ECG is shown. The pattern remains unchanged after 1 minute. Which of the following is the most appropriate intervention?