Analysis of J waves during myocardial ischaemia

Division of Cardiology, Niigata University Graduate School of Medical and Dental Sciences, 1-754 Asahimachi-dori, Chuo-Ku, Niigata-City, Niigata 951-8510, Japan.
Europace (Impact Factor: 3.67). 10/2011; 14(5):715-23. DOI: 10.1093/europace/eur323
Source: PubMed


The aim of this study was to investigate the relationship between J-wave dynamics and arrhythmias during myocardial ischaemia in patients with vasospastic angina (VSA).
Sixty-seven consecutive patients diagnosed with VSA by a provocation test for coronary spasm were grouped according to whether they had a J wave in the baseline electrocardiograms or not (VSA-JW group, n = 14; VSA-non-JW group: n = 53). We retrospectively studied the associations between J-wave and ST-segment dynamics and induced ventricular fibrillations (VFs) during coronary spasm. In the VSA-JW group, 7 of the 14 patients showed changes in J-wave morphology and/or gains in J-wave voltage, followed by VF in 4 patients. Compared with patients without VF, the four patients with VF showed similar maximal voltage in the baseline J waves but a higher voltage during induced coronary spasms (0.57 ± 0.49 vs. 0.30 ± 0.11 mV; P = 0.011). In three patients with VF, J waves progressively increased and were accompanied by the characteristic coved-type or lambda-shaped ST-segment elevations. In the VSA-non-JW group, only four patients showed new appearances of J waves during coronary spasms and another patient without a distinct J wave developed VF. Ventricular fibrillations were induced more frequently in the VSA-JW group than in the VSA-non-JW group [4/14 (29%) vs. 1/53 (2%); P = 0.012].
J-wave augmentations were caused by myocardial ischaemia during coronary spasms. The presence and augmentation of J waves, especially prominent J waves with the characteristic ST-elevation patterns, were associated with VF.

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