A 56-year-old man presents to the emergency room with nausea, vomiting, muscle cramps, and weakness that began three days ago. Five days ago, he started taking Penicillin G for acute pharyngitis and has been using it regularly along with his other medications: lisinopril, atorvastatin, and spironolactone. On physical examination, he appears anxious and distressed, has difficulty walking, and shows decreased sensations and reflexes in all four extremities. Laboratory studies reveal a potassium level of 6.8 mmol/L. An ECG reveals changes consistent with hyperkalemia. Which of the following medications can contribute to this condition?

A 48-year-old male with a history of liver cirrhosis is undergoing a minor surgical procedure for excision of a skin lesion. The patient was injected with 30 mL of 2% lidocaine (600 mg) without epinephrine for local anesthesia. Shortly after the injection, he reports a metallic taste in his mouth, dizziness, and ringing in his ears. Within minutes, he develops perioral numbness and confusion, followed by generalized muscle twitching. The patient becomes drowsy but responsive, with involuntary muscle twitching. Blood pressure was 140/90 mmHg, heart rate 98 bpm, and oxygen saturation was 96% on room air. His weight was 60 kg. Within moments, he becomes unresponsive and experiences a tonic-clonic seizure lasting approximately 30 seconds. After the cessation of seizure, his blood pressure drops to 80/50 mmHg, and his heart rate falls to 40 bpm, with signs of cardiovascular collapse. What is the most effective antidote to treat cardiovascular collapse in this patient?

A 13 year-old female is brought to the emergency room because she has been spitting up blood stained sputum for the last three days. She is having shortness of breath even with a short walk and passing out with exertion. Often her skin, lips and nails turn a bluish tone. Physical examination shows cyanosis in the lips and digital clubbing in both upper extremities. On auscultation, first heart sound is normal and P2 is markedly accentuated; a soft holosystolic murmur is heard in the tricuspid area and a long diastolic murmur is heard in the pulmonary area. A chest x-ray showed right ventricular enlargement with filling in of the retrosternal air space; dilated central pulmonary arteries, abrupt attenuation and termination of peripheral pulmonary artery branches. ECG showed normal voltages and no beat-to-beat variation; it revealed the right atrial enlargement and right ventricular hypertrophy with a rightward axis. Echocardiogram corroborates the findings observed on chest x ray and ECG. Patient could not finish the 6-minute walk testing (6MWT). Which of the following is most likely found in this patient?

A 6-month-old boy is brought to your pediatric cardiology clinic for evaluation of a murmur heard by his primary care physician. His mother reports that he is healthy and active, with no shortness of breath or recurrent infections beyond what is typical for other children his age. On physical examination, the boy appears well-nourished and appropriately sized. Auscultation reveals a harsh, holosystolic murmur at the left lower sternal border, with no cyanosis or clubbing. Further family history reveals that the mother’s brother was diagnosed with Holt-Oram syndrome. Which of the following is a characteristic feature of Holt-Oram syndrome?

A 6-month-old boy is brought to your pediatric cardiology clinic for evaluation of a murmur that was heard during a routine check-up by his primary care physician. His mother reports that he is healthy and active, with no episodes of shortness of breath or frequent infections. On physical examination, he appears well-nourished and appropriately sized for his age. Auscultation reveals a harsh, holosystolic murmur at the left lower sternal border. There is no cyanosis or clubbing. An echocardiogram reveals a small, isolated ventricular septal defect (VSD) with a left-to-right shunt. What is the most appropriate next step in the management of this patient?