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Risk stratification of lethal arrhythmias is important for the management of ischemic heart disease. Recently, we developed a novel 187-channel signal-averaged vector-projected high-resolution electrocardiograph (187-ch SAVP-ECG) with a Mason–Likar lead system with 10 electrodes. The purpose of this study was to examine the feasibility of a noninvasive evaluation of the spatial distribution of high-frequency late potentials (HFLPs) in patients with myocardial infarction (MI) by using the 187-ch SAVP-ECG. Sixty-four MI patients (7 women and 57 men), between the age of 39 and 84 years (mean 67.7±9.7 years), with positive ventricular late potentials defined by an X, Y, Z-lead ECG were studied. The integrated ventricular 187-ch SAVP-ECG could identify the area of HFLPs that was projected virtually by mathematically calculated 187 electrograms on the body surface in all patients, and differentiate the locations of MI. The 187-ch SAVP-ECG can be a practical and noninvasive examination tool for identifying the location of infarction areas and possible arrhythmogenic substrates with slow conduction properties in patients with MI.

Background: It is unclear whether depression persists in patients with implantable cardioverter defibrillators (ICDs). We evaluated the prevalence and persistence of depression in ICD patients over a 2-year period. Methods: The study included 90 consecutively hospitalized patients. Patients underlying heart disease was 24% coronary artery disease, 29% idiopathic dilated cardiomyopathy, 24% hypertrophic cardiomyopathy, 13% idiopathic VF/long QT syndrome and miscellaneous conditions 11%. A secondary indication for ICD implantation was present in 20 patients. All patients completed the Zung Self-Rating Depression Scale (SDS) at study baseline and at the their routine follow-up visit 2 years after the baseline questionnaire. Delivery of ICD therapies was tracked throughout the 2 years. Results: Depression, indicated by a Zung SDS index score exceeding 60, was present in 29 (32%) of patients at study baseline. Depression was present in 11/51 (21%) patients scheduled to undergo ICD implantation, 2/2 (100%) patients whose device was upgraded to a CRT-D, 3/14 (21%) patients who had undergone pulse generator replacement, 7/14 (50%) patients who experienced electrical storm and 6/9 (66%) patients hospitalized with acute decompensated heart failure. NYHA functional class III was significantly associated with depression at baseline (HR 6.7, 95% CI 1.68–27.2, p = 0.0007). No differences were noted for female gender, demographics, β-blocker use, or LVEF ≤35% (p = ns). Depression was present in 25 (28%) of patients at 2 years follow-up, persisting in 21 (72%) of patients whose Zung SDS scores were elevated at baseline. The median time from ICD shock therapy to completion of the 2 year questionnaire was 9 months (range, 1–22). Patients who were depressed (9/25, 36%) experienced more shocks than non-depressed patients (6/65, 9%) after 2 years (p = 0.002). Conclusions: Depression is not uncommon among patients who meet criteria for ICD implantation and persists over time particularly when functional status is impaired. Depression is associated with a higher incidence shock therapy. (PACE 2010; 33:1455–1461)

Introduction: Amiodarone infusion has been recommended for life-threatening ventricular arrhythmias. However its effectiveness in Japanese patients has not yet been determined. Methods: This was an uncontrolled, open-label trial involving patients with hemodynamically unstable ventricular tachycardia (VT) or ventricular fibrillation (VF). Intravenous amiodarone was delivered as a 125 mg bolus followed by infusion of 50 mg/h for 6 hours, then 25 mg/h for 42 hours. The primary endpoint for efficacy was the proportion of patients free from hemodynamically unstable VT/VF at 48-hour. Secondary endpoints included: event frequency; proportion of patients event-free, treatment outcome, and safety. Results: Forty-seven patients were enrolled. Forty-one patients were evaluated for efficacy and safety parameters were assessed for all 47 patients. The proportion of patients free from hemodynamically unstable VT/VF was 53.9%; the proportion of patients free from hemodynamically unstable VT/VF relapse or whose treatment was discontinued was 48.8%. Eight patients died; all deaths were judged, by the investigator, as being unrelated to amiodarone. No cases of torsades de pointes were reported. Mild abnormal thyroid function was noted in one patient. No cases of interstitial lung disease or pulmonary fibrosis were observed. Conclusion: Amiodarone infusion provides a useful tool in preventing acute relapse of lifethreatening ventricular arrhythmias in Japanese patients.

Human ABCA8, a new member of the ATP binding cassette (ABC) transporter family, transports certain lipophilic drugs, such as digoxin. To investigate the roles of this transporter, we cloned a mouse homologue of ABCA8, from a mouse heart cDNA library, named ABCA8a. The deduced mouse ABCA8a protein is 66% identical with that of human ABCA8 and possesses features common to the ABC superfamily. It was found that ABCA8a was mainly expressed in the liver and heart, similar to human ABCA8. We further evaluated the effect of acute digoxin (a substrate for ABCA8) intoxication on the mRNA expression of ABCA8 using northern blotting with a 3' non-coding region as a probe to avoid cross-hybridization with other ABCA genes. Following acute digoxin infusion, the mRNA expression of ABCA8 was significantly reduced in the liver 12-24 h after injection (14.7% of vehicle treatment), but not in the heart and kidney. Real-time quantitative polymerase chain reaction analysis confirmed the reduction in ABCA8a mRNA. Similar reductions in ABCA5, ABCA7, ABCA8b and ABCA9 mRNA were also observed. A comparable amount of digitoxin did not affect ABCA8a mRNA expression in the liver. The results suggest that ABCA8 may play a role in digoxin metabolism in the liver.

A patient with infective endocarditis (IE) due to methicillin-resistant staphylococcus aureus (MRSA) was found to have conversion of the hypoechoic region of the posterior mitral valve ring apparatus into a clearly delineated echolucent space by repeating transthoracic echocardiography at an interval of 1 week. Color Doppler showed features of blood entry into this space. Abscess formation in IE due to MRSA may be quick and repeated echocardiography may help detect the complications of IE. Semiurgent mitral valve plasty was performed for the associated prolapse of the posterior mitral leaflet using a hand-made, rolled, twisted autologous pericardial ring.

Aims HMG-CoA reductase inhibitors (statins) have been demonstrated to have in vitro vascular effects. The aim of this study was to determine whether statins actually have in vivo vascular effects independent of their cholesterol-lowering effect.

The purpose of the present study was to evaluate the feasibility and efficacy of stenting following suboptimal percutaneous transluminal coronary angioplasty (PTCA) in angiographically small coronary arteries. The clinical and angiographic outcome of unplanned stenting in 33 patients with coronary arteries

The class Ic anti-arrhythmic agent, flecainide is known to inhibit the transient outward K current (Ito) selectively in human atrium. We studied the effects of propafenone, another class Ic anti-arrhythmic agent, on K currents in human atrial myocytes using a whole-cell voltage-clamp method. Propafenone inhibited both Ito and the sustained or ultra-rapid delayed rectifier K current (Isus or Ikur) evoked by depolarization pulses. The concentration for half-maximal inhibition (IC50) was 4.9 μM for Ito and 8.6 μM for Isus. Propafenone blocked Ito and Isus in a voltage- and use-independent fashion and accelerated the inactivation time constant of Ito [from 28.3 to 6.7 ms at 10 μM propafenone]. The steady-state inactivation curve for Ito was unaffected by propafenone. Propafenone did not affect the initial current at depolarizing potentials, but it did produce a block that increased as a function of time after depolarization (time constant of 3.4 ms). This suggests that propafenone preferentially blocked Ito in the open state. Propafenone had no significant effect on the rate at which Ito recovered from inactivation at −80 mV suggesting that propafenone dissociates rapidly from the channel. The steady-state activation curve for Isus was not affected by propafenone. Propafenone slowed the time course of the onset of the Isus tail current. This suggests that propafenone blocked Isus in the open state. The present results suggest that, unlike flecainide, propafenone blocks both Ito and Isus in human atrial myocytes in the open state at clinically relevant concentrations. British Journal of Pharmacology (1999) 126, 1153–1162; doi:10.1038/sj.bjp.0702428

The purpose of the present study was to determine the clinical significance of consecutive automatic shocks delivered by implantable cardioverter defibrillators (ICDs). Sixty-four patients who received ICDs at our institution between January 1990 and July 1997 were included in this study. There were 53 men and 11 women with a mean age of 50 +/- 14 years. During a follow-up period ranging between 0.2 and 73 months (mean 23 +/- 21 months), 17 patients received consecutive shocks (group A), 29 patients received single shocks (group B), and 18 patients received no ICD therapy (group C). Clinical characteristics, episodes of ICD therapy, and prognosis were compared among the three groups. There were no significant differences among the three groups with regard to clinical characteristics, time to first ICD therapy, number of antitachycardia pacing episodes, or frequency of inappropriate discharges. The mortality rate was higher in group A than in groups B and C (P = 0.0021). The sensitivity of consecutive shocks in predicting death was 70%, the specificity was 88%, and the predictive accuracy was 81% in patients with left ventricular ejection fractions < 35%. In summary, consecutive shocks are a clinically important event in patients with ICDs. Specifically, patients who receive consecutive shocks and have a depressed left ventricular function should be considered particularly high risk.

1. To determine the contribution of the various phosphodiesterase (PDE) isozymes to the regulation of the L-type calcium current (ICa(L)) in the human myocardium, we investigated the effect of selective and non-selective PDE inhibitors on ICa(L) in single human atrial cells by use of the whole-cell patch-clamp method. We repeated some experiments in rabbit atrial myocytes, to make a species comparison. 2. In human atrial cells, 100 microM pimobendan increased ICa(L) (evoked by depolarization to +10 mV from a holding potential of -40 mV) by 250.4 +/- 45.0% (n = 15), with the concentration for half-maximal stimulation (EC50) being 1.13 microM. ICa(L) was increased by 100 microM UD-CG 212 by 174.5 +/- 30.2% (n = 10) with an EC50 value of 1.78 microM in human atrial cells. These two agents inhibit PDE III selectively. 3. A selective PDE IV inhibitor, rolipram (1-100 microM), did not itself affect ICa(L) in human atrial cells. However, 100 microM rolipram significantly enhanced the effect of 100 microM UD-CG 212 on ICa(L) (increase with UD-CG 212 alone, 167.9 +/- 33.9, n = 5; increase with the two agents together, 270.0 +/- 52.2%; n = 5, P < 0.05). Rolipram also enhanced isoprenaline (5 nM)-stimulated ICa(L) by 52.9 +/- 9.3% (n = 5) in human atrial cells. 4. In rabbit atrial cells, ICa(L) at +10 mV was increased by 22.1 +/- 9.0% by UD-CG 212 (n = 10) and by 67.4 +/- 12.0% (n = 10) by pimobendan (each at 100 microM). These values were significantly lower than those obtained in human atrial cells (P < 0.0001). Rolipram (1-100 microM) did not itself affect ICa(L) in rabbit atrial cells. However, ICa(L) was increased by 215.7 +/- 65.2% (n = 10) by the combination of 100 microM UD-CG 212 and 100 microM rolipram. This value was almost 10 times larger than that obtained for the effect of 100 microM UD-CG 212 alone. 5. These results imply a species difference: in the human atrium, the PDE III isoform seems dominant, whereas PDE IV may be more important in the rabbit atrium for regulating ICa(L). However, PDE IV might contribute significantly to the regulation of intracellular cyclic AMP in human myocardium when PDE III is already inhibited or when the myocardium is under beta-adrenoceptor-mediated stimulation.

We studied the influence of early coronary reperfusion on QT interval dispersion in patients with acute myocardial infarction (MI). There were 54 males and 18 females with a mean age of 60 +/- 10 years. Of the 51 patients with recanalization of the infarct related vessel in the recovery phase, 28 (group A) had early coronary reperfusion (5.5 +/- 2.7 hours), 23 other patients (group B) were not confirmed with early coronary reperfusion. Twenty-one patients (group C) did not undergo recanalization of the infarct related vessel in the recovery phase. Corrected QT (QTc) maximum, QTc minimum, and QTc dispersion calculated as the difference between the maximum and minimum QTc intervals, were compared among these three groups at both acute and recovery phase. At the acute phase after MI, there were no significant differences in the QTc maximum, QTc minimum, QT dispersion, and QTc dispersion among these three groups. At the recovery phase after MI, there were also no significant differences in the QTc maximum and QTc minimum. However, there were significant differences in the QT dispersion (0.035 +/- 0.010 in group A, 0.049 +/- 0.015 in group B, and 0.061 +/- 0.031 s in group C, respectively; P = 0.0001), and QTc dispersion (0.038 +/- 0.012 in group A, 0.050 +/- 0.015 in group B, and 0.063 +/- 0.032 s in group C, respectively; P = 0.0003) among the three groups. Comparison of QTc dispersion between acute and recovery phase revealed significant reduction from acute to recovery phase in group A. The number of premature ventricular contraction was lower in group A and B than group C. In summary, early coronary reperfusion may reduce electrophysiological instability by reducing QT dispersion in the recovery phase after acute MI.

A 56-year-old man was referred to our hospital for a catheter ablation of paroxysmal supraventricular tachycardia. An echocardiogram on admission revealed no abnormalities. During an electrophysiological study, the clinical tachycardia was induced by programmed atrial stimuli, and we diagnosed it as an orthodromic atrioventricular reentrant tachycardia (AVRT) that utilized a posteroseptal concealed accessory pathway as the retrograde conduction limb. Via a retrograde aortic approach, a 4 mm tip ablation catheter was inserted from the femoral artery, and an RF application was then delivered using the temperature control mode, limited to 60◦C. Immediately after delivering the RF application, the retrograde conduction via the accessory pathway was eliminated. However, soon after that, the patient’s blood pressure fell rapidly, following an audible “POP.” We promptly diagnosed it as an acute cardiac tamponade, and thus reversed

Poly-chloroparaxylene (parylene) is widely used as a material for cardiac pacemaker coating. Contact sensitivity to parylene was proven by patch test. Wrapping the pacemaker in a polytetrafluoroethylene sheet prior to implantation prevented further skin reactions.

A noninvasive method has been applied on human and canine subjects to observe beat-to-beat activity of the His-Purkinje system without using signal averaging. Recordings were performed with multiple Ag/AgCl electrodes, very low noise, high gain amplifiers and by analog filtering. The subjects were in a supine position during the recording. In order to reduce random noise inherent in the high-gain body surface recording, a finite element method (FEM) was applied to calculate His-Purkinje activity. The dimensional relationship between electrode sites, necessary for the calculation, was pre-estimated by x-ray computed tomographs of the subject. A prominent waveform was observed between the atrial and ventricular complexes and corresponded to His bundle activity which was simultaneously recorded by an intracardiac electrode (on every beat). It was, however, difficult to recognize the His-Purkinje activity during inhalation due to the thoracic electromyogram on some human subjects. This interference could theoretically be reduced by increasing the number of body surface electrodes used for this technique.