S. Sharma et al., Utility of metabolic exercise testing in distinguishing hypertrophic cardiomyopathy from physiologic left ventricular hypertrophy in athletes, J AM COL C, 36(3), 2000, pp. 864-870
Citations number
46
Categorie Soggetti
Cardiovascular & Respiratory Systems","Cardiovascular & Hematology Research
OBJECTIVES This study evaluated the role of metabolic (cardiopulmonary gas
exchange) exercise testing in differentiating physiologic LVH in athletes f
rom HCM.
BACKGROUNDS Regular intensive training may cause mild increases in left ven
tricular wall thickness (LVWT). Although the degree of left ventricular hyp
ertrophy (LVH) is typically less than chat seen in hypertrophic cardiomyopa
thy (HCM), genetic studies have shown that a substantial minority of patien
ts with HCN have an LVWT in the same range. The differentiation of physiolo
gic and pathologic LVH in this "gray zone" can be problematic using echocar
diography and electrocardiography alone.
METHODS Eight athletic men with genetically proven HCM and mild LVH (13.9 /- 1.1 mm) and eight elite male athletes matched for age, size and LVWT (13
.4 +/- 0.9 mm) underwent symptom limited metabolic exercise stress testing.
Peak oxygen consumption (pVO(2)), anaerobic threshold, oxygen pulse and re
spiratory exchange ratios were measured in both groups and compared with th
ose observed in 12 elite and 12 recreational age- and size-matched athletes
without LVH.
RESULTS Elite athletes with LVH had significantly greater pVO(2) (66.2 +/-
4.1 ml/kg/min vs. 34.3 +/- 4.1 ml/kg/min; p < 0.0001), anaerobic threshold
(61.6 +/- 1.8% of the predicted maximum VO2 vs. 41.4 +/- 4.9% of the predic
ted maximum VO2; p < 0.001) and oxygen pulse (27.1 +/- 3.2 ml/beat vs. 14.3
+/- 1.8 ml/beat; p < 0.0001) than individuals with HCM. A pVO(2), >50 ml/k
g/min or >20% above the predicted maximum VO2 differentiated athlete's hear
t from HCM.
CONCLUSIONS Metabolic exercise testing facilitates the differentiation betw
een physiologic LVH and HCM in individuals in the "gray zone" (C) 2000 by t
he American College of Cardiology.