Journal of electrocardiology
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Case Reports
Wellens syndrome associated with prominent anterior QRS forces: an expression of left septal fascicular block?
Wellens syndrome is a clinical-electrocardiographic entity also referred to as left anterior descending (LAD) coronary T-wave syndrome or acute coronary T-wave syndrome. It is a complex of symptoms and signals indicating the existence of an undesirable condition secondary to critical high-grade proximal stenosis of the LAD coronary artery characterized by the association of prior history of acute coronary syndrome with little or no elevation of markers of myocardial damage (unstable angina) and characteristic electrocardiographic changes consistent with subepicardial anterior ischemic pattern (persistently symmetrical, deep negative and broad-based T waves) or plus-minus T waves with inversion of the terminal portion in the LAD coronary artery territory (V1 through V5 or V6). We present a case of a variant of Wellens syndrome that reveals association and, transitorily, the criteria described in literature for left septal fascicular block.
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An important subset of patients (approximately 10%) with chest pain and ST-segment elevation on initial electrocardiogram (ECG) do not have acute coronary occlusion. In our experience, 5% of women presenting with chest pain and ST-segment elevation are proven to have the newly recognized syndrome of tako-tsubo (stress) cardiomyopathy (TC). Patients with TC present with clinical and electrocardiographic features mimicking ST-segment elevation anterior myocardial infarction due to left anterior descending (LAD) occlusion. ⋯ In conclusion, patients with TC frequently present with anterior ST-segment elevation, which cannot be reliably distinguished from that of acute LAD occlusion. In TC, the combination of minimal troponin release, absent delayed hyperenhancement on cardiac magnetic resonance imaging (in most of patients), and return to normal LVEF is consistent with the presence of significant myocardial stunning. The ECG evolution of progressive T-wave inversion, QTc interval lengthening, and R-wave reappearance could be the electrophysiologic manifestation of an underlying stunned myocardium in this condition.
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There is currently a challenge to produce an electrocardiogram (ECG) recording of waveforms that are "standard" and also achieve the "noise immunity" required for continuous monitoring. The potential solutions that have been considered are to label each torso-recorded ECG as "nonstandard, torso-recorded," designate torso placement as "standard," or to reconstruct the "equivalent distally recorded ECG." The purpose of the present study was to validate an alternative "Lund system" of proximal limb electrode sites as a clinically feasible solution to this challenge. ⋯ Indeed, the Lund system replicated distal waveforms at a clinically acceptable level. Studies of larger patient cohorts including patients with various cardiac pathologies and studies of the noise immunity attained should be performed, and the acceptability by health care professionals should be determined.