Tom L. is a 23-year-old marathon runner. Nearing Central Park at about the 20-mile mark of the New York Marathon, he suddenly turns pale, clutches his chest, and drops to the ground. Another runner, although on pace for a personal best, stops to help. Finding Tom pulseless and apneic, he begins cardiopulmonary resuscitation. The timely intervention proves lifesaving. Tom responds, and moments later, the following EKG is taken as he is being rushed to the nearest hospital. Why did Tom collapse?

CASE STUDY

1. Futile efforts to memorize all of the EKG criteria for left ventricular hypertrophy), comes to your office for a routine checkup. She is new to your practice and has not seen a doctor since her last child was born, which was more than 20 years ago. She has no specific complaints other than an occasional headache. Routine physical examination is unremarkable, except that you find her blood pressure is 170/110 mm Hg. She is unaware of being hypertensive. You would like to know if her hypertension is long-standing or of recent onset. Your laboratory assessment includes measurement of serum electrolytes, creatinine, and blood urea nitrogen; a urinalysis; a chest x-ray; and the EKG shown below. Is the EKG helpful?

2.Tom L. is a 23-year-old marathon runner. Nearing Central Park at about the 20-mile mark of the New York Marathon, he suddenly turns pale, clutches his chest, and drops to the ground. Another runner, although on pace for a personal best, stops to help. Finding Tom pulseless and apneic, he begins cardiopulmonary resuscitation. The timely intervention proves lifesaving. Tom responds, and moments later, the following EKG is taken as he is being rushed to the nearest hospital. Why did Tom collapse?