Increased QT Dispersion in Patients With Vasospastic Angina

Nishizaki, Mitsuhiro; Arita, Masataka; Ashikaga, Takashi; Yamawake, Noriyoshi; Kakuta, Tsunekazu; Numano, Fujío; Hiraoka, Masayasu

doi:10.1161/01.cir.98.5.435

Cited by 72 publications

(52 citation statements)

References 44 publications

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“…[7][8][9] In the present study, 4 cases of polymorphic VT showed a pattern of torsade de pointes, which was frequently encountered in the presence of a prolonged QT interval. The polymorphic VT with a torsade de pointes pattern was infrequently noted with normal Q-T interval in the early stage of an acute myocardial infarction.…”

Section: Possible Mechanism Of Spontaneous Polymorphic Vt During Corosupporting

confidence: 50%

“…8 Here we evaluated ventricular vulnerability by programmed ventricular stimulation in 5 patients with spontaneous VT at baseline who did not have any sign of myocardial ischemia. Consequently, polymorphic VT was induced in 2 of the 5 patients, with 1 patient developing ventricular fibrillation.…”

Section: Possible Mechanism Of Spontaneous Polymorphic Vt During Coromentioning

confidence: 99%

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Polymorphic Ventricular Tachycardia in Patients With Vasospastic Angina

et al. 2001

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he clinical characteristics and mechanism of polymorphic ventricular tachycardia (VT) in the setting of prolonged Q-T interval have extensively been studied, 1-3 but polymorphic VT with normal Q-T interval has infrequently been reported and most reports concern its development in the early stage of acute myocardial infarction. 4,5 Eisenberg et al described 15 patients who exhibited polymorphic VT and normal QT interval in the absence of apparent structural heart disease, 6 and of these he found that only 2 had polymorphic VT during episodes of coronary artery spasm.Recently, using electrophysiologic studies (EPS) and examination of QT dispersion on 12-lead surface ECG, we reported that patients with vasospastic angina (VSA) exhibit inhomogeneity of ventricular repolarization and increased ventricular vulnerability, even during the symptom-free period. 7-9 These life-threatening ventricular arrhythmias are one of the most serious complication of ischemic attack caused by coronary spasm, and are associated with an Japanese Circulation Journal Vol. 65, June 2001 increased risk of sudden cardiac death. [10][11][12][13][14] However, to the best of our knowledge, there have been few clinical studies exploring the clinical and electrocardiographic characteristics and prospective long-term follow-up of spontaneous polymorphic VT developing during a vasospastic attack. Therefore, we investigated the characteristics of spontaneous polymorhpic VT in patients withVSA and their longterm outcome. Methods PatientsThe study group comprised 60 Japanese patients with VSA (44 men, 16 women; mean age, 56 years [range, 44-75 years]) consecutively enrolled at Yokohama Minami Kyosai Hospital (single institution) from April 1991 to March 1995. All patients with VSA had a spontaneous episode of angina and coronary vasospasm, defined as total or subtotal (99% with delay) occlusion, or a severe constriction of the vessel associated with myocardial ischemic ST segment changes on ECG and chest pain after the intracoronary injection of acetylcholine. No symptomatic significant coronary stenosis on baseline angiograms and no history of myocardial infarction were noted in any of the 60 patients. None had evidence of cardiomyopathy, congestive heart failure, peptic ulcer, chronic obstructive lung disease or other serious cardiopulmonary diseases. All patients had normal ventricular function without segmental wall motion abnormality on the resting M-mode and 2-dimensional echocardiogram. Doppler echocardiograms revealed no abnormalities in any

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Section: Possible Mechanism Of Spontaneous Polymorphic Vt During Corosupporting

confidence: 50%

Section: Possible Mechanism Of Spontaneous Polymorphic Vt During Coromentioning

confidence: 99%

Polymorphic Ventricular Tachycardia in Patients With Vasospastic Angina

et al. 2001

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“…QT dispersion and cardiac disease: Increased QT dispersion reflects electrical inhomogeneity, which may occur as a result of myocardial ischemia, mitral valve prolapse, ventricular hypertrophy or dilatation, autonomic neuropathy, peripheral vascular disease, and hypertension. [9][10][11][12][13][14][15] A recent study, which analyzed the 12-lead electrocardiograms of 1501 healthy adults and 1784 healthy children found that QTd was age and sex independent.…”

Section: Discussionmentioning

confidence: 99%

“…In patients with vasospastic angina, it was found that QTc dispersion was increased and this was associated with ventricular arrhythmias. 9) In a study of 182 patients with non-insulin dependent diabetes mellitus, QTd, QTcd, and QTc max were reported to be accurate predictors of cardiac death. 17) None of our subjects had overt diabetes mellitus (Table I).…”

Section: Discussionmentioning

confidence: 99%

QT Dispersion in Patients with Polycystic Ovary Syndrome.

et al. 2002

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SUMMARYCardiac risk factors are observed more frequently in patients with polycystic ovary syndrome (PCOS). On the other hand, increased QT dispersion, which is a risk factor for cardiac arrhythmias and sudden death, has not been investigated in this syndrome. In this study, we evaluated QT dispersion in PCOS patients without overt heart disease. Thirtysix consecutive women with PCOS (mean age 24±5 years) and 36 healthy women of similar ages (mean age 24±4 years) participated in this study. PCOS was diagnosed if there were polycystic ovaries by ultrasound (enlarged ovaries with ≥8 cysts 2-8 mm in diameter), oligoamenorrhea (intermenstrual interval >35 days), hirsutism (Ferriman-Gallwey score, ≥7) and elevated serum levels of testosterone (≥2.7 nmol/L). Electrocardiograms were recorded at a paper speed of 50 mm/s. QT intervals were manually measured by a cardiologist. All intervals were corrected for heart rate according to Bazett's formula: QTc interval=QT interval/square root of the RR interval. Mean values of body mass index, heart rate, and blood pressure were not significantly different between the two groups (P>0.05). No significant differences in QT intervals (maximum QT, minimum QT, QT dispersion, minimum corrected QT, maximum corrected QT, and corrected QT dispersion) were observed between the two groups (P>0.05). Our results suggest that the risk of ventricular arrhythmias or sudden cardiac death is not increased in PCOS patients. (Jpn Heart J 2002; 43: 487-493) Key words: Electrocardiography, Polycystic ovary syndrome, QT dispersion POLYCYSTIC ovary syndrome (PCOS) is a disorder of chronic anovulation, hyperandrogenism, hirsutism, obesity, subfertility, hyperlipidemia, and insulin resistance. Infertility is not the only important component of this syndrome, since the risks of cardiac disease and hypertension also increase in women with PCOS.1-3) Insulin resistance and hyperinsulinemia appear central to the pathophysiology of PCOS. Glucose intolerance, abnormally high fasting serum lipid concentrations, and high blood pressure are the three cardiac risk factors that have From the

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“…16 In the present study, all subjects were subjected to coronary angiography and were diagnosed as having no significant coronary artery stenosis. Moreover, the possibility of vasospastic angina was ruled out on the results of the methylergometrine maleate test.…”

Section: Discussionmentioning

confidence: 99%

Influence of Exercise on QT Dispersion in Hypertensive Patients With Left Ventricular Hypertrophy Without Coronary Artery Disease

Yoshimura¹,

Matsumoto²,

Watanabe³

et al. 1999

Jpn Circ J

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n hypertension, left ventricular hypertrophy (LVH) predicts an increased morbidity and mortality due to the occurrence of ventricular arrhythmias. 1,2 QT dispersion (QTD), which is defined as the difference between the maximum and minimum QT intervals occurring in any of the 12 leads of the electrocardiogram (ECG), is a reflection of the regional variation in ventricular repolarization and is believed to have predictive value in the assessment of the risk for ventricular arrhythmia. 3,4 An ECG at rest showing increased QTD has recently been reported to be a characteristic of hypertensives with LVH. 5,6 However, little is known about the QTD measured after exercise. Hypertension is a risk factor for coronary artery disease in patients who have been shown to have increased QTD. 4 When the effects of LVH in hypertension on QTD are evaluated, the effects of coronary artery disease, through which hypertension complicates QTD, should be excluded. To rule out coronary artery diseases completely, coronary angiography is desirable.We investigated the effect of exercise on QTD using the treadmill stress test in hypertensive patients with LVH who had undergone coronary angiography and had no coronary artery stenosis. Japanese Circulation Journal Vol.63, November 1999 Methods SubjectsWe studied 70 patients with essential hypertension (EH). Hypertension was defined as a systolic blood pressure of greater than 140 mmHg and/or diastolic blood pressure of more than 90 mmHg on at least 3 different occasions. All subjects underwent treadmill stress tests and coronary angiography. All of them showed negative exercise stress test results, defined by standard ST-segment depression criteria, and had no significant coronary artery stenosis or vasospasm. If the patients had taken antihypertensive drugs, the administration of these was stopped at least 2 weeks before the study. Subjects who had suffered a myocardial infarction, atrial fibrillation, or presented with bundle branch block were excluded. Approval for this study was obtained from the institution's Ethics Committee, and written informed consent was obtained from each subject. The 70 patients were divided into 2 groups on the basis of the echocardiographic measurement of their left ventricular mass index (LVMI). Hypertensive patients with LVH consisted of 7 men and 13 women; the hypertensives without LVH were 23 men and 27 women. Coronary AngiographyAll participants underwent coronary angiography and had no coronary artery disease, defined as one or more vessels with stenosis of 50% or more. Methylergometrine maleate (Novartis, Tokyo, Japan), dissolved in 20 ml of 0.9% saline, in incremental doses of 20 and 40 g, was injected over 2 min into the coronary artery to exclude vasospastic angina. A positive methylergometrine maleate Jpn Circ J 1999; 63: 881 -884 (Received June 18, 1999; revised manuscript received July 28, 1999; accepted August 9, 1999 In hypertensive patients with left ventricular hypertrophy (LVH), the influence of exercise on the regional variations in ventri...

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Increased QT Dispersion in Patients With Vasospastic Angina

Cited by 72 publications

References 44 publications

Polymorphic Ventricular Tachycardia in Patients With Vasospastic Angina

Polymorphic Ventricular Tachycardia in Patients With Vasospastic Angina

QT Dispersion in Patients with Polycystic Ovary Syndrome.

Influence of Exercise on QT Dispersion in Hypertensive Patients With Left Ventricular Hypertrophy Without Coronary Artery Disease

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