Lectus

A 68-year-old man with chronic obstructive pulmonary disease is admitted to the hospital with an acute exacerbation. His ECG shows an irregular rhythm with at least three different P-wave morphologies and a ventricular rate of 140 beats per minute, consistent with multifocal atrial tachycardia. His blood pressure is 110/70 mmHg and oxygen saturation is 88% on room air. Which of the following medications would be most appropriate for rate control in this patient?Deselect Answer

A 45-year-old man presents with rectal bleeding and fatigue for the past 3 months. His father was diagnosed with colorectal cancer at age 48, and his paternal uncle had multiple colon polyps removed at age 52. Colonoscopy reveals approximately 40 adenomatous polyps throughout the colon. Genetic testing is performed, which identifies biallelic mutations in a gene involved in DNA repair. Histologic examination of a biopsy specimen from one of the polyps shows an increase in G:C to T:A transversions. Which of the following best describes the underlying genetic defect in this patient?Deselect Answer

A 64-year-old man presents with a unilateral severe chest pain that started a day ago. He describes the chest pain as sharp in nature and predominantly localized to his right side. He also complains of mild shortness of breath but says that it is tolerable. He denies any recent history of fever, sweating, dizziness, or similar episodes in the past. His past medical history is significant for chronic lymphocytic leukemia for which he was started on chemotherapy. He has currently completed 3 cycles with the last one ending a few days ago. His temperature is 36.5°C (97.7°F), blood pressure is 118/75 mm Hg, pulse is 95/min, and respirations are 20/min. The lungs are clear to auscultation bilaterally. There is severe tenderness to palpation over the right chest and a painful stripe of vesicular lesions, but there is no evidence of bruising or trauma. An electrocardiogram is normal and a chest radiograph is unremarkable. Cardiac enzymes are pending. Laboratory studies show:

Which of the following is the best course of treatment for this patient?Deselect Answer

A 5-year-old boy is brought to the pediatrician due to concerns about skin lesions and developmental delays. Physical examination reveals multiple hypopigmented macules on his trunk and extremities, facial angiofibromas across his cheeks, and a shagreen patch on his lower back. Brain MRI shows multiple cortical tubers and subependymal nodules. Genetic testing would most likely show a mutation in which of the following genes?Deselect Answer