OBJECTIVES: This study was designed to assess the relation between rest left ventricular function and exercise capacity in patients with syndrome X. BACKGROUND: Clinical observation has suggested that some patients with syndrome X have a high rest left ventricular ejection fraction. In this study we determined the relation between left ventricular ejection fraction and exercise capacity and the electrocardiographic (ECG) changes that develop on exercise. METHODS: The pattern of left ventricular function, exercise capacity and 24-h ambulatory ECG monitoring were studied in 37 patients (9 men, 28 women; mean age 52 +/- 7 years) with syndrome X (angina with normal coronary arteries and a positive exercise test result). All patients had normal findings on echocardiogram and rest ECG. All treatment was discontinued for > or = 48 h. Left ventricular ejection fraction was determined by computerized analysis of the left ventricular angiogram. In patients with syndrome X, exercise duration and heart rate were measured at 1-mm ST segment depression and at peak exercise. RESULTS: Left ventricular hypercontractility (ejection fraction > or = 80%) was observed in 12 patients (32%) (group 1), whereas 25 patients (68%) had normal left ventricular contraction (group 2). The time to 1-mm ST depression on exercise testing was significantly earlier in group 1 than in group 2 (5.13 +/- 1.03 vs. 10.76 +/- 0.63 min, respectively, p < 0.001). The magnitude of the ST segment depression at peak exercise was significantly greater in group 1 than in group 2 (2.03 +/- 0.2 vs. 1.33 +/- 0.05 mm, respectively, p < 0.001). The mean time for ST segment depression to normalize was significantly greater in group 1 than in group 2 (4.76 +/- 0.78 vs. 3.16 +/- 0.39 min, respectively, p < 0.05). Linear regression analysis of all patients with syndrome X showed a significant correlation between exercise duration and ejection fraction (r = 0.55, p < 0.001). The mean circadian variation of heart rate and episodes of ST segment depression on 24-h ambulatory ECG monitoring were similar in the two groups of patients. CONCLUSIONS: These findings indicate that approximately one third of patients with chest pain, normal coronary angiograms and a positive exercise test have left ventricular hypercontractility, and this is associated with the development of ST segment depression at a lower heart rate and work load and a longer time to normalization of ST segment depression after exercise.
OBJECTIVES: This study was designed to assess the relation between rest left ventricular function and exercise capacity in patients with syndrome X. BACKGROUND: Clinical observation has suggested that some patients with syndrome X have a high rest left ventricular ejection fraction. In this study we determined the relation between left ventricular ejection fraction and exercise capacity and the electrocardiographic (ECG) changes that develop on exercise. METHODS: The pattern of left ventricular function, exercise capacity and 24-h ambulatory ECG monitoring were studied in 37 patients (9 men, 28 women; mean age 52 +/- 7 years) with syndrome X (angina with normal coronary arteries and a positive exercise test result). All patients had normal findings on echocardiogram and rest ECG. All treatment was discontinued for > or = 48 h. Left ventricular ejection fraction was determined by computerized analysis of the left ventricular angiogram. In patients with syndrome X, exercise duration and heart rate were measured at 1-mm ST segment depression and at peak exercise. RESULTS:Left ventricular hypercontractility (ejection fraction > or = 80%) was observed in 12 patients (32%) (group 1), whereas 25 patients (68%) had normal left ventricular contraction (group 2). The time to 1-mm ST depression on exercise testing was significantly earlier in group 1 than in group 2 (5.13 +/- 1.03 vs. 10.76 +/- 0.63 min, respectively, p < 0.001). The magnitude of the ST segment depression at peak exercise was significantly greater in group 1 than in group 2 (2.03 +/- 0.2 vs. 1.33 +/- 0.05 mm, respectively, p < 0.001). The mean time for ST segment depression to normalize was significantly greater in group 1 than in group 2 (4.76 +/- 0.78 vs. 3.16 +/- 0.39 min, respectively, p < 0.05). Linear regression analysis of all patients with syndrome X showed a significant correlation between exercise duration and ejection fraction (r = 0.55, p < 0.001). The mean circadian variation of heart rate and episodes of ST segment depression on 24-h ambulatory ECG monitoring were similar in the two groups of patients. CONCLUSIONS: These findings indicate that approximately one third of patients with chest pain, normal coronary angiograms and a positive exercise test have left ventricular hypercontractility, and this is associated with the development of ST segment depression at a lower heart rate and work load and a longer time to normalization of ST segment depression after exercise.
Authors: Catherine Gebhard; Monika Maredziak; Michael Messerli; Ronny R Buechel; Fay Lin; Heidi Gransar; Stephan Achenbach; Mouaz H Al-Mallah; Daniele Andreini; Jeroen J Bax; Daniel S Berman; Matthew J Budoff; Filippo Cademartiri; Tracy Q Callister; Hyuk-Jae Chang; Kavitha Chinnaiyan; Benjamin J W Chow; Ricardo C Cury; Augustin DeLago; Gudrun Feuchtner; Martin Hadamitzky; Joerg Hausleiter; Yong-Jin Kim; Jonathon Leipsic; Erica Maffei; Hugo Marques; Pedro de Araújo Gonçalves; Gianluca Pontone; Gilbert L Raff; Ronen Rubinshtein; Leslee J Shaw; Todd C Villines; Yao Lu; Erica C Jones; Jessica M Peña; James K Min; Philipp A Kaufmann Journal: Eur Heart J Cardiovasc Imaging Date: 2020-04-01 Impact factor: 6.875
Authors: Ahmed Haider; Susan Bengs; Monika Maredziak; Michael Messerli; Michael Fiechter; Andreas A Giannopoulos; Valerie Treyer; Moritz Schwyzer; Christel Hermann Kamani; Dimitri Patriki; Elia von Felten; Dominik C Benz; Tobias A Fuchs; Christoph Gräni; Aju P Pazhenkottil; Philipp A Kaufmann; Ronny R Buechel; Catherine Gebhard Journal: Eur J Nucl Med Mol Imaging Date: 2019-01-16 Impact factor: 9.236