Successful Treatment of Refractory Electrical Storm With Landiolol After More Than 100 Electrical Defibrillations.

Electrical storm (ES) was observed in an 82-year-old man with recent myocardial infarction. Conventional therapy, including amiodarone, could not suppress the ES. After more than 100 electrical defibrillations, we were finally able to control the ES with the administration of landiolol. It is known that landiolol can inhibit ES. However, we hesitate to use landiolol in patients with low cardiac output. We would like to emphasize that careful use of landiolol should be considered in patients with refractory ES after myocardial infarction, although cardiac output is severely reduced.

Deep anesthesia suppresses ventricular tachyarrhythmias in rabbit model of the acquired long QT syndrome.

BACKGROUND: Anesthesia sometimes suppresses ventricular tachyarrhythmias (VT) resistant to conventional pharmacological treatment. METHODS AND RESULTS: To know (1) whether deep anesthesia inhibits abnormal repolarization-related VT and (2) if α2-adrenoreceptor (AR) agonistic action is associated with the antiarrhythmic effect of anesthetics, the incidence of VT in a rabbit model of acquired long QT syndrome using different anesthetic regimen was assessed. In Study 1 (n = 30), 15 rabbits were lightly anesthetized with ketamine (123 ± 46 mg/kg) and an α2-AR agonist, xylazine (9.4±3.0mg/kg), while combination of these anesthetics at high doses were used in the other 15 rabbits (343 ± 78 mg/kg and 38.9 ± 3.0 mg/kg). Administration of α1-AR stimulant, methoxamine and nifekalant (Ikr blocker) caused VT in all lightly anesthetized rabbits. In contrast, VT was observed only in 1 of the 15 deeply anesthetized rabbits (P < 0.01). In Study 2 (n = 15), 10 rabbits were anesthetized with high-dose ketamine and low-dose xylazine. In the other 5 rabbits, low-dose ketamine and high-dose xylazine were used. QTc interval in the latter was longer than that of the former (399 ± 56 ms vs. 494 ± 57 ms, P < 0.01). Although no VT appeared in high/low-rabbits, VT occurred in 3 out of 5 low/high-rabbits (P < 0.05). CONCLUSIONS: These results suggest that (1) deep anesthesia suppresses abnormal repolarization-related VT and (2) antiarrhythmic effect of anesthesia on this type of VT is not dependent on α2-AR agonistic action.

Long-term outcome of acute myocardial infarction patients treated with stents versus balloon angioplasty: results from randomized trials.

AIM: To examine the impact of primary stent implantation versus balloon angioplasty on long-term outcome (median 8 years) in 117 patients with ST-elevation myocardial infarction (STEMI) from randomized trials. METHODS: Enrolled patients were those presenting with STEMI within 12 h of symptom onset. Patients were randomized to either Palmaz-Schatz stent implantation (N=25) or balloon angioplasty (N=23) between January and November 1996; or Palmaz-Schatz (N=26), or Cordis coil stent implantation (N=24) or balloon angioplasty (N=19) between February 1998 and March 1999. RESULTS: Patients (67+/-11 years) arrived to the hospital within median 2.5 h of symptom onset with Killip 1/2/3/4 grade (72/19/7/2%, respectively). The culprit lesion was located in the left anterior descending (50%), right (39%), or left circumflex coronary artery (11%) with TIMI 0/1/2/3 flow (81/5/12/2%, respectively). Clinical/angiographic features were comparable between the 2 groups. During follow-up, there was a significant reduction in cardiac mortality in the stent group (5%) compared to the angioplasty group (17%, log-rank test p=0.04). In addition, the stent group had a lower target lesion revascularization rate (28% versus 52%, p=0.008), and a significantly lower major adverse cardiac event rate (37% versus 67%, p=0.005), than the angioplasty group. CONCLUSION: Compared to balloon angioplasty, primary stenting resulted in a sustained beneficial effect on cardiac mortality at 8 years.

Human atrial natriuretic peptide suppresses torsades de pointes in rabbits.

BACKGROUND: The increase in inward current, primarily L-type Ca2+ current, facilitates torsades de pointes (TdP). Because human atrial natriuretic peptide (ANP) moderates the L-type Ca2+ current, in our study it was hypothesized that ANP counteracts TdP. METHODS AND RESULTS: We tested the effect of ANP, guanosine 3', 5'-cyclic monophosphate analogue (8-bromo cGMP) and hydralazine on the occurrence of TdP in a rabbit model. In control rabbits, administration of methoxamine and nifekalant almost invariably caused TdP (14/15). In contrast, ANP (10 microg . kg(-1) . min(-1)) markedly abolished TdP (2/15), whereas hydralazine failed to show a comparable anti-arrhythmic action (10/15). TdP occurred only in 1 of 15 rabbits treated with 8-bromo cGMP. Presence of early afterdepolarization-like hump in the ventricular monophasic action potential was associated with the occurrence of TdP. CONCLUSION: Results suggest that ANP affects TdP in the rabbit model, and that this anti-arrhythmic effect of ANP is not necessarily shared by other vasodilating agents.