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Titolo:
Exercise-induced ST-segment depression: imbalance between myocardial oxygen demand and myocardial blood flow
Autore:
Watanabe, T; Akutsu, Y; Yamanaka, H; Michihata, T; Okazaki, O; Katagiri, T; Harumi, K;
Indirizzi:
Showa Univ, Sch Med, Dept Internal Med 3, Tokyo, Japan Showa Univ Tokyo Japan Univ, Sch Med, Dept Internal Med 3, Tokyo, Japan
Titolo Testata:
ACTA CARDIOLOGICA
fascicolo: 1, volume: 55, anno: 2000,
pagine: 25 - 31
SICI:
0001-5385(200002)55:1<25:ESDIBM>2.0.ZU;2-0
Fonte:
ISI
Lingua:
ENG
Soggetto:
POSITRON-EMISSION-TOMOGRAPHY; AMERICAN-HEART-ASSOCIATION; CORONARY-ARTERY DISEASE; N-13 AMMONIA; TASK-FORCE; ELECTROCARDIOGRAPHY; GUIDELINES; COMMITTEE; ISCHEMIA;
Keywords:
ST-segment depression; myocardial ischemia; rate-pressure product; regional myocardial blood flow; positron emission tomography;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Clinical Medicine
Citazioni:
25
Recensione:
Indirizzi per estratti:
Indirizzo: Watanabe, T Univ Texas, Sch Med, Dept Internal Med, Div Cardiol, 6431 Fannin,MSB 6-039, Houston, TX 77030 USA Univ Texas 6431 Fannin,MSB 6-039 Houston TX USA 77030 7030 USA
Citazione:
T. Watanabe et al., "Exercise-induced ST-segment depression: imbalance between myocardial oxygen demand and myocardial blood flow", ACT CARDIOL, 55(1), 2000, pp. 25-31

Abstract

Objective - ST-segment depression is believed as a common electrocardiographic sign of myocardial ischemia during exercise testing. Ischemia is generally defined as oxygen deprivation due to reduced perfusion. However, the exact relationship of the ischemic definition to ST-segment depression remains unclear. This study was conducted to evaluate the correlation between myocardial oxygen demand and myocardial blood flow (MBF) when ischemic (horizontal or downsloping) ST-segment depression of greater than or equal to 0.1mV 80 ms after the J point developed during low-level exercise. Methods and results - Seventy-two patients with angiographically proven coronary artery disease (CAD) and 9 healthy volunteers underwent exercise positron emission tomography (PET), Myocardial oxygen demand was defined as a rate-pressure product (RPP, heart rate x systolic blood pressure) during exercise and MBF was quantified by nitrogen-13 ammonia perfusion PET. The myocardial demand-supply balance (MDSB) index was calculated from the MBF ratio (values during exercise/values at rest) against the RPP ratio (values during exercise/values at rest). The MDSB index was significantly lower in patients with ischemic ST-segment depression than in patients with non-ischemic ST depression and healthy volunteers (0.82 +/- 0.16 vs. 1.02 +/- 0.17, p < 0.0001 and vs. 0.99 +/- 0.14, p = 0.0109). Further, the presence of inadequate increase in MBF of less than or equal to 10% (2 SD below the mean % value of healthy volunteers) during exercise in regional myocardium perfusedby stenotic CAD significantly correlated with exercise-induced ischemic ST-segment depression (p = 0.0105),Conclusions - Our study could demonstrate that exercise-induced ischemic ST-segment depression is associated with myocardial ischemia due to exercise-induced imbalance between myocardial oxygen demand and global and regionalMBF supply in patients with proven CAD.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 18/01/20 alle ore 13:15:05