Question: What would you do next? Answer: C

Further risk stratification needed The patient has already optimized his lifestyle and is exceeding current physical activity guidelines.1 He is asymptomatic without clear evidence of ischemia or acute coronary syndrome, so jumping to invasive coronary angiography for his coronary artery calcifications would not be appropriate at this time. Medical management may be indicated, so his 10-year ASCVD Risk is calculated and found to be borderline at 5.1%. Initiation of a low dose aspirin and a moderate intensity statin therapy are both IIb recommendations and can be considered if other risk-enhancing factors are present.2 He is therefore sent for labs and studies for further risk stratification. Lipoprotein (a) is elevated at 198 nmol/L, high sensitivity CRP <0.2 mg/L, and hemoglobin A1c is 5.3%. A two-week external rhythm monitor to assess his symptomatic palpitations demonstrated sinus rhythm ranging from 37 bpm to 162 bpm with an average rate of 56 bpm. Patient triggered events on the monitor during episodes of post-exercise palpitations showed brief runs of an irregular supraventricular tachycardia with a maximum rate of 200 bpm and the longest run lasting 14 beats at average rate of 94 bpm. There are rare premature ventricular contractions seen but no ventricular runs. A CT coronary calcium score reveals a total Agatston score of 2085, placing him in the 99th percentile. The distribution shows no calcium in the left main, 461 in the left anterior descending, 347 in the left circumflex, and 1278 in the right coronary artery.

What is the next appropriate step? Answer: B

Exercise stress testing Given his significant coronary calcium burden in the 99th percentile, a high dose statin is more appropriate. A beta blocker is certainly reasonable but requires an informed discussion with athletes as it can be tolerated poorly with a reduction in exercise heart rate and capacity. CT coronary angiography could be useful to evaluate plaque morphology, but can be challenging in the setting of a high calcium burden with reduced sensitivity and positive predictive value due to extensive blooming artifact. Invasive angiography would be preferred if the patient had chest pain, decreased systolic function, ischemia on stress testing, or ventricular arrhythmias, which have not been demonstrated in this patient. He agreed to start taking aspirin 81 mg daily and high intensity statin therapy with rosuvastatin 20 mg daily. He then underwent cardiopulmonary exercise testing with stress echocardiography imaging. He exercised on a recumbent bicycle with ramp protocol, reaching a peak work rate of 262 W, heart rate of 163 bpm (101%MPHR), and a VO 2 Max of 41.1 ml/kg/min (141% predicted). Anaerobic threshold was calculated at 206 W using the V-slope method and occurred at a heart rate of 146 bpm. He experienced no symptoms or arrhythmias during or after peak exercise and had no evidence of ischemia by electrocardiogram or echocardiography. Repeat lipid panel on statin therapy showed a reduction in total cholesterol to 168 mg/dL, HDL 88 mg/dL, LDL 69 mg/dL, and triglycerides 56 mg/dL. He is cleared to continue his current level of exercise, predominantly in the aerobic range based on his CPET test results. He is given instructions on symptoms to monitor for during exercise, as well as precautions for when to seek emergency care. He has done well so far with no statin-induced myopathy symptoms, ischemic symptoms or events.

Question: Which of the following tests will most likely show the cause of her symptoms? Answer: C

Tilt table testing The patient’s symptoms are concerning for autonomic dysfunction after a viral infection. She has atypical features not concerning for angina, so a stress test or cardiac CT would not likely show ischemia. A cardiac MRI could be useful in showing inflammation but would not likely explain her symptoms. She was therefore sent for autonomic reflex testing. Valsalva maneuver also reproduced symptoms, but beat-to-beat blood pressure response was normal. Tilt table testing showed severe symptomatic orthostatic intolerance with lightheadedness, blurry vision, chest tightness, and shortness of breath with head-up tilt at 70º. End-tidal CO2 was reduced after 3 minutes in head-up tilt. She remained in regular sinus rhythm. Her heart rate increased from 61 to 116 bpm, and her blood pressure rose inappropriately, from 106/68 to 110/76 mmHg. She had reduced mean cerebral blood flow velocity in the right middle cerebral artery as much as 35% during head up tilt at 70 degrees compared with baseline, consistent with postural orthostatic tachycardia syndrome (POTS).

Authors: Christine P. Shen, MD; Sandeep R. Mehta, MD, Division of Cardiology, Scripps Clinic

Question: What is the next appropriate step for this patient? Answer: A

Lifestyle management with salt and fluid loading, compression stockings, and graded exercise. POTS is best treated initially with lifestyle management with salt and fluid loading, compression stockings, and graded exercise. Patients should drink 2-3 L of water per day, consume salt 10-12 g/day, and wear compression stockings. Patients should start a graded, structured, and supervised exercise program. Propranolol at a low-dose can help with sinus tachycardia and palpitations. Fludrocortisone and Midodrine have been used if symptoms persist after lifestyle management. Authors: Christine P. Shen, MD; Sandeep R. Mehta, MD, Division of Cardiology, Scripps Clinic

Question 1 of 2 How should you counsel him on whether he should play in the upcoming football season? Answer is B

Given the features that raise significant concern for ACM, the patient should be advised that participation in high intensity competitive athletics increases his risk of ventricular arrhythmia and sudden death (2,3). ICD may be reasonable for some patients with ACM and a history of sudden cardiac arrest, sustained ventricular tachycardia, LV ejection fraction <45%, and those with multiple major and minor disease criteria (2). In patients without an ICD, beta blockers are a reasonable therapeutic option to reduce the risk of arrhythmia (Class IIa, Level of Evidence: C).

Question 2 of 2 Which of the following may be helpful in establishing a formal diagnosis? Answer is C

The patient meets several of the 2020 Padua criteria for LV variant of ACM (known as ALVC) (4). However, in patients with normal RV findings, it is suggested that ACM not be diagnosed solely off LV phenotypic criteria due to overlap with conditions such as dilated cardiomyopathy, hypertrophic cardiomyopathy, and cardiac sarcoidosis. In this patient with several clinical findings suggestive of arrhythmogenic cardiomyopathy (ACM), identification of a pathogenic mutation association with ACM would allow for the diagnosis of ALVC by Padua criteria. Identification of first and second degree relatives with confirmed ACM consist of major and minor Padua criteria, respectively, however, they are insufficient to confirm diagnosis of ALVC. A right bundle branch block pattern of ventricular tachycardia is a minor Padua criteria, insufficient to confirm diagnosis of ALVC.  

In our patient, genetic testing of the Arrhythmia and Cardiomyopathy Comprehensive Panel (Invitae) of 67 inherited genes did not reveal any mutations associated with ACM or other cardiomyopathy. Thus, a formal diagnosis of ALVC was not able to be made by Padua criteria.