An 8-year-old boy with a known moderate-sized ventricular septal defect is noted to have a significant improvement in his exercise tolerance over the past year. On exam, his holosystolic murmur has become a harsher systolic ejection murmur, and a new electrocardiogram shows progression of right ventricular hypertrophy. This clinical evolution is most suggestive of which developing process?
A 16-year-old boy is diagnosed with hypertrophic cardiomyopathy (HCM). His asymptomatic 14-year-old sister is being evaluated. A comprehensive genetic testing panel is ordered for the family. What is the most appropriate initial step in the genetic testing process for this family?
A 7-month-old infant is brought to the clinic for poor weight gain and increased work of breathing, especially during feeding. On examination, he is tachycardic, has a gallop rhythm, and hepatomegaly. An echocardiogram shows a dilated left ventricle with severely decreased systolic function. Which type of cardiomyopathy do these findings represent?
A 4-month-old infant with d-transposition of the great arteries and a large ventricular septal defect is awaiting surgical repair. The infant is stable but has signs of increasing pulmonary overcirculation. Which long-term complication is this infant at unusually rapid risk of developing compared to a child with an isolated large ventricular septal defect?
A fetus at 32 weeks gestation is diagnosed with hypoplastic left heart syndrome, with aortic and mitral atresia. Despite the severity of this lesion, the fetus shows appropriate growth and no signs of hydrops fetalis. Which fetal circulatory pathway is most critical for maintaining both systemic and coronary arterial perfusion in this situation?
A 2-day-old neonate with a structurally normal heart develops atrial flutter with an atrial rate of 450 beats/min and a 2:1 atrioventricular block, resulting in a ventricular rate of 225 beats/min. After successful synchronized DC cardioversion to sinus rhythm, what is the most appropriate long-term management strategy?
A 14-year-old boy presents with a 3-day history of sharp chest pain that radiates to his shoulders. He notes the pain is worse when he lies down or takes a deep breath, and it feels better when he sits up and leans forward. A friction rub is heard on auscultation. These findings are most characteristic of which condition?
A 6-year-old boy with repaired tetralogy of Fallot presents for a follow-up visit. He is asymptomatic with good exercise tolerance. On auscultation, a to-and-fro murmur is heard at the left sternal border. This finding is most commonly indicative of what residual hemodynamic state?
A newborn is diagnosed with an interrupted aortic arch, type B. On examination, the infant has a cleft palate and develops hypocalcemic seizures on the second day of life. Genetic testing confirms a 22q11.2 deletion. Which statement accurately describes the recurrence risk for this condition?
A 16-year-old soccer player experiences syncope during practice. He has no prior symptoms, but his father died suddenly at age 40 from a heart condition. An evaluation reveals an anomalous origin of the left main coronary artery from the right sinus of Valsalva. This anomaly is associated with sudden death due to what mechanism during exercise?