[Functional capacity and rhythm changes after atrial correction of transposition of great arteries]. / Capacidad funcional y alteraciones del ritmo después de corrección auricular de la transposición de las grandes arterias.

A group of 12 patients, previously submitted to atrial correction of the transposition of the great vessels, were studied through stress test with direct metabolimetry and Holter to assess aerobic functional capacity and its relationship with conduction disturbances. The results were compared with those obtained with a control group of 23 non athletic healthy children. All the patients showed amputation of their heart rates on effort, though this parameter and the oxygen consumption were normal at low work load levels. The VO2 at anaerobic threshold, the maximum VO2, and the maximum work load were also decreased in most of the patients. Holter studies demonstrated sick sinus syndrome in nine of them. Aerobic functional capacity was reduced in most of the patients with atrial correction of the transposition of the great vessels. The amputation of the heart rate on effort is a common finding though its relationship with the decrease of the aerobic functional capacity in these patients is limited. Finally, the stress test is probably more sensible than Holter for the detection of slight degrees of sinus disfunction.

Diagnostic value of stress testing in the elderly.

The exercise tests performed by 197 patients aged 65 years or more (mean age 68.8) have been reviewed, including 43 healthy subjects, 20 with high blood pressure, 10 with mitral valve disease and 125 with demonstrated coronary artery disease. All tests were done on an electrical cycloergometer, with load increases of 30 W every 3 min. Eighty-four (42.6%) achieved at least 85% of their maximal predicted heart rate. The reasons for non-achievement of this heart rate were limitation by symptoms (30.2%), betablocker therapy (25.8), exhaustion (20.2%), pain in lower extremities (14%) and non-adaptation to cycloergometer (10%). The maximum load achieved and the duration of exercise were significantly lower in mitral and coronary patients. Functional aerobic capacity was decreased in coronary and mitral patients. The VO2 max was directly determined in 45 patients. Mean values (ml kg-1 min-1) were 33.3 +/- 3.5 in normals, 15.4 +/- 6.2 in coronary and 15.8 +/- 4.1 in mitral patients. The incidence of arrhythmias during exercise was higher in hypertensive (55%) than in mitral (40%), normal (33.3%) and coronary patients (32.8%). In 5 patients the test had to be interrupted because of ventricular tachycardia. The yield of ST depression (greater than 0.1 mV) or elevation (greater than 0.2 mV) in the diagnosis of coronary artery disease was 0.62 sensitivity and 0.93 specificity. We conclude that stress test is a useful tool in cardiovascular diagnosis among older patients.(ABSTRACT TRUNCATED AT 250 WORDS)