Exercise testing and Thallium-201 myocardial perfusion scintigraphy in the clinical evaluation of patients with Wolff Parkinson White syndrome

• Published in: Journal of electrocardiology Vol. 19; no. 4; pp. 319 - 326
• Main Authors: Poyatos, Maria Elena, Suarez, Luis, Lerman, Jorge, Guibourg, Haydee, Camps, Julio, Perosio, Albino
• Format: Journal Article
• Language: English
• Published: Orlando, FL Elsevier Inc 01.10.1986; Philadelphia, PA Churchill Livingstone
• Subjects: Adolescent; Adult; Angina Pectoris - diagnostic imaging; Biological and medical sciences; Cardiac dysrhythmias; Cardiology. Vascular system; Coronary Circulation; Coronary Disease - diagnostic imaging; Electrocardiography; Exercise Test; Female; Heart; Heart Rate; Humans; Male; Medical sciences; Middle Aged; Myocardial Infarction - diagnostic imaging; Prospective Studies; Radioisotopes; Radionuclide Imaging; Thallium; Wolff-Parkinson-White Syndrome - diagnostic imaging; Radionuclide study; Human; Electrodiagnosis; Arrhythmia; Perfusion; Myocardium; Cardiovascular disease; Exercise tolerance test; Wolff Parkinson White syndrome; Hemodynamics; Scintigraphy; Coronary vessel
• ISSN: 0022-0736; 1532-8430
• DOI: 10.1016/S0022-0736(86)81059-7

In 58 patients with Wolff Parkinson White syndrome (WPW), we performed exercise stress testing in order to investigate the incidence of normalization of the auriculo-ventricular conduction and the ST-segment changes. For a more accurate evaluation of the latter, exercise and redistribution radionuclide images with Thallium-201 were obtained in 18 cases. Forty-nine had type A and nine had type B of WPW. Forty-eight had permanent, four had alternant and six had no pre-excitation (PE) when they started the test. Mean maximal functional capacity, mean maximal heart rate and mean maximal double product were not different when compared to an age-matched control group. Of the 48 patients who began the test with PE, in 23 (48%) it disappeared while PE persisted in 25 (52%). In 16 cases the disappearance of the PE was sudden and in seven it was progressive. Preexcitation persisted in 39.5% of patients with type A and in 88.8% with type B (p<0.01). ST-segment depression was observed in 76.6% of patients with PE and in 28.6% of cases without PE (p<0.01). ST-segment depression occurred in 44.8% of patients with type A and in 100% of cases with type B (p<0.05). Transient abnormal Thallium-201 scans were observed in 62.5% of patients without PE and in 20% with PE. No patient showed exertional arrhythmias. This study suggests the possibility of measuring the duration of the refractory period of the accessory pathway in those patients in which the PE disappears suddenly, at a given heart rate. This has prognostic value because the probability of occurrence of severe tachyarrhythmias is higher as the refractory period of the anomalous way is shorter. Another conclusion of this study is the low specificity of ST-segment depression after exercise in patients with WPW, even in the cases in which PE disappears.