BACKGROUND: There is a heightened risk of sudden cardiac death related to exercise and the postexercise recovery period, but the precise mechanism is unknown. We have demonstrated that sympathoexcitation persists for ≥45 minutes after exercise in normals and subjects with coronary artery disease (CAD). The purpose of this study is to determine whether this persistent sympathoexcitation is associated with persistent heart rate variability (HRV) and ventricular repolarization changes in the postexercise recovery period. METHODS AND RESULTS: Twenty control subjects (age 50.7 ± 1.4 years), 68 subjects (age 58.2 ± 1.5 years) with CAD and preserved left ventricular ejection fraction (LVEF), and 18 subjects (age 57.6 ± 2.4 years) with CAD and depressed LVEF underwent a 16-minute submaximal bicycle exercise protocol with continuous ECG monitoring. QT and RR intervals were measured in recovery to calculate the time dependent corrected QT intervals (QTc), the QT-RR relationship, and HRV. QTc was dependent on the choice of rate correction formula. There were no differences in QT-RR slopes among the three groups in early recovery. HRV recovered quickly in controls, more slowly in those with CAD-preserved LVEF, and to a lesser extent in those with CAD-depressed LVEF. CONCLUSION: Despite persistent sympathoexcitation for the 45-minute recovery period, ventricular repolarization changes do not persist for that long and HRV changes differ by group. Additional understanding of the dynamic changes in cardiac parameters after exercise is needed to explore the mechanism of increased sudden cardiac death risk at this time.
BACKGROUND: There is a heightened risk of sudden cardiac death related to exercise and the postexercise recovery period, but the precise mechanism is unknown. We have demonstrated that sympathoexcitation persists for ≥45 minutes after exercise in normals and subjects with coronary artery disease (CAD). The purpose of this study is to determine whether this persistent sympathoexcitation is associated with persistent heart rate variability (HRV) and ventricular repolarization changes in the postexercise recovery period. METHODS AND RESULTS: Twenty control subjects (age 50.7 ± 1.4 years), 68 subjects (age 58.2 ± 1.5 years) with CAD and preserved left ventricular ejection fraction (LVEF), and 18 subjects (age 57.6 ± 2.4 years) with CAD and depressed LVEF underwent a 16-minute submaximal bicycle exercise protocol with continuous ECG monitoring. QT and RR intervals were measured in recovery to calculate the time dependent corrected QT intervals (QTc), the QT-RR relationship, and HRV. QTc was dependent on the choice of rate correction formula. There were no differences in QT-RR slopes among the three groups in early recovery. HRV recovered quickly in controls, more slowly in those with CAD-preserved LVEF, and to a lesser extent in those with CAD-depressed LVEF. CONCLUSION: Despite persistent sympathoexcitation for the 45-minute recovery period, ventricular repolarization changes do not persist for that long and HRV changes differ by group. Additional understanding of the dynamic changes in cardiac parameters after exercise is needed to explore the mechanism of increased sudden cardiac death risk at this time.
Authors: K Shetler; R Marcus; V F Froelicher; S Vora; D Kalisetti; M Prakash; D Do; J Myers Journal: J Am Coll Cardiol Date: 2001-12 Impact factor: 24.094
Authors: Velislav N Batchvarov; Azad Ghuran; Peter Smetana; Katerina Hnatkova; Monica Harries; Polychronis Dilaveris; A John Camm; Marek Malik Journal: Am J Physiol Heart Circ Physiol Date: 2002-06 Impact factor: 4.733
Authors: S Zhou; J M Cao; Z D Tebb; T Ohara; H L Huang; C Omichi; M H Lee; B H Kenknight; L S Chen; M C Fishbein; H S Karagueuzian; P S Chen Journal: J Cardiovasc Electrophysiol Date: 2001-09
Authors: Maria Angela Magalhães de Queiroz Carreira; André Barros Nogueira; Felipe Montes Pena; Marcio Galindo Kiuchi; Ronaldo Campos Rodrigues; Rodrigo da Rocha Rodrigues; Jorge Paulo Strogoff de Matos; Jocemir Ronaldo Lugon Journal: Arq Bras Cardiol Date: 2015-05-05 Impact factor: 2.000