PMC9792272_01
Electrocardiographic findings on admission. Sinus tachycardia (heart rate, 106 bpm) with ST elevation and depression in the anterior leads and the lateral and inferior leads, respectively. QT prolongation was also documented (472 msec).
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Electrocardiogram revealed ST-segment elevation in the anterior leads with long QT (QTc, 472 msec) (Figure 1).
Coronary angiography on admission and after percutaneous coronary intervention. Severe stenosis of the left anterior descending artery, left circumflex artery (A, B) and total occlusion of the right coronary artery (C) with collaterals from the septal branch and left circumflex artery to the distal portion of the right coronary artery (arrows). Drug-eluting stents were implanted in the proximal portion of the left anterior descending artery, left circumflex artery (D) and proximal to the distal portion of the right coronary artery (E). LCA, left coronary artery; RCA, right coronary artery.
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ST-segment elevation myocardial infarction with congestive heart failure. Subsequently, emergency coronary angiography was performed, revealing three-vessel disease, with severe stenosis of the left anterior descending artery (LAD), left circumflex artery (LCX) and total occlusion of the right coronary artery (RCA) (Figure 2A-C). Rentrop Grade 2 collaterals were observed from the septal branch and LCX to the distal portion of the RCA (Figure 2B). Although drug-eluting stents were implanted in the proximal segment of the LAD and LCX (Figure 2D), VT/VFs did not decrease; therefore, RCA was also re-vascularized the following day (Figure 2E).
Initiation of ventricular arrhythmia. QT prolongation and frequent premature ventricular contractions were documented immediately before electrical storm occurred (A). Electrical storm occurred due to R-on-T phenomenon (arrows) (B).
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After complete coronary revascularization, ventricular arrhythmia prevalence decreased; however, VT/VFs occurred easily due to the R-on-T phenomenon associated with QT prolongation (Figure 3).
Clinical course of the patient. After revascularization, the number of cardioversions decreased, but ventricular arrhythmia did not disappear. Stellate ganglion blockade was initiated on the 9th day of hospitalization. On discontinuing SGB, ventricular arrhythmia rapidly increased. Combined therapy with stellate ganglion blockade and nifekalant completely suppressed ventricular arrhythmia. AAD, antiarrhythmic drug; IABP, intra-aortic balloon pumping; LAD, left anterior descending artery; LCX, left circumflex artery; PCI, percutaneous coronary intervention; RCA, right coronary artery; VA-ECMO, veno-arterial extracorporeal membrane oxygenation.
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SGB and nifekalant, the VT/VFs suddenly disappeared, and no recurrence was observed during the rest of the patient's hospital stay (Figure 4). Subsequently, haemodynamic status became stable, and IABP was explanted during hospitalization Day 19.