Even in the era of thrombus aspiration and distal protection for ST-segment elevation acute myocardial infarction (STEMI), microvascular dysfunction does exist and improvement of microvascular dysfunction can improve the prognosis and/or left ventricular dysfunction. We evaluated the acute effects of nitroprusside (NTP) on coronary microvascular injury that occurred after primary percutaneous coronary intervention (PCI) for STEMI in 18 patients. The final Thrombolysis in Myocardial Infarction trial (TIMI) flow grade after PCI was 3 in 17 patients and 2 in 1 patient. The index of microcirculatory resistance (IMR) was improved significantly from 76 ± 42 to 45 ± 37 (P = 0.0006) by intracoronary NTP administration. IMR improved to the normal range (IMR < 30) in 9 patients (50%). Higher TIMI flow grade and lower IMR at baseline were observed more frequently in patients whose IMR recovered to normal range after NTP administration. NTP improved the microcirculatory dysfunction at the acute phase in patients who underwent PCI for STEMI and had final TIMI 3 flow in almost all cases.

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Intravascular ultrasound studies have shown that patients with unstable angina pectoris (UAP) more frequently had soft plaques in the culprit coronary arteries than patients with stable angina pectoris (SAP). We evaluated coronary plaque characteristics of culprit lesions in patients with UAP by 64-slice computed tomographic coronary angiography (64-slice CTCA). 64-slice CTCA (Aquilion 64, Toshiba Medical Systems, Otawara, Japan) was performed in 30 patients (UAP = 14, SAP = 16) before percutaneous coronary intervention (PCI). Coronary plaque area was measured by manual tracing for the difference between the area within the external elastic membrane and the area of the vessel lumen at the site of maximal luminal narrowing as observed on a cross-sectional 64-slice CTCA image where PCI was performed. Within this plaque area, CT low-density plaque area (< 50 Hounsfield units) was automatically calculated. There were no differences in stenotic rate and whole plaque area of the culprit lesion between patients with UAP and SAP. However, the CT low-density plaque area was significantly greater in patients with UAP than in those with SAP. A greater area of CT low-density plaque in the culprit lesion is associated with UAP rather than SAP. Measuring CT-low density plaque area on 64-slice CTCA images could be useful for understanding the clinical setting of UAP.

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This study aimed to evaluate the degree of reduction in walking speed in patients with acute myocardial infarction (AMI) compared to age-matched community-dwelling people and identify factors associated with walking speed. The subjects were 210 middle-aged and 188 elderly patients with a first AMI (AMI group) and 198 age-matched community-dwelling people with no medical events (non-AMI group). We measured maximum walking speed in all subjects and collected clinical data, including that related to motor function, at the end of a supervised cardiac rehabilitation program in the AMI group. Data were analyzed based on age and sex. Walking speed in men and women in the middle-aged AMI subgroup decreased to 77.9% and 75.7% relative to that of the non-AMI subgroup matched by sex, respectively; walking speed in men and women in the elderly AMI subgroup decreased to 78.7% and 74.2% relative to that of the non-AMI subgroup matched by sex, respectively. Moreover, 6.4% of men and 23.8% of women in the middle-aged AMI subgroup, and 28.8% of men and 43.5% of women in the elderly AMI subgroup, had a slower walking speed compared to their respective non-AMI groups, which may contribute to an increased risk for cardiovascular mortality. Stepwise multiple regression analysis for motor function revealed that only leg strength in the middle-aged AMI subgroup, and both leg strength and standing balance in the elderly AMI subgroup, were associated with walking speed, regardless of sex after adjusting for clinical characteristics. These results suggest that evaluation and management of walking speed are necessary in implementing effective disease management for patients with first AMI.

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Ventricular desynchronization imposed by ventricular pacing causes regional disturbances of adrenergic innervation in the left ventricular myocardium and increases the risk of heart failure and atrial fibrillation (AF) in patients with sinus node disease (SND). As a result, decreased iodine-123 metaiodobenzylguanidine (I-¹²³ MIBG) uptake occurs in patients with an implanted permanent pacemaker. Fourteen SND patients with an implanted pacemaker equipped with an algorithm for reducing unnecessary right ventricular pacing (RURVP) were enrolled. Pacemakers were programmed to RURVP mode for the first 12 weeks, and then reprogrammed to DDD for the last 12 weeks. At the end of each mode, data on cumulative percent ventricular pacing (%Vp), atrial high rate episodes (%AHR), I-¹²³ MIBG myocardial scintigraphy, brain natriuretic peptide (BNP), human atrial natriuretic peptide (hANP), and myocardial damage indices typified by troponin T and C-reactive protein (CRP) were collected. %Vp was lower in RURVP than in DDD (0.2% versus 95.7%, P = 0.00098). BNP, hANP, troponin T, and CRP did not differ significantly between the pacing modes. However, I-¹²³ MIBG findings of patients with full ventricular pacing in DDD improved in RURVP. In contrast, among patients without full ventricular pacing in DDD, their I-¹²³ MIBG findings did not differ significantly between the pacing modes. In SND patients with normal cardiac function and intact atrioventricular conduction, the reduction of %Vp in RURVP was due to the reduction of ineffective pacing and fusion pacing in DDD. Therefore, these 2 types of pacing do not affect cardiac pump function.

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The goal of this prospective study was to examine the effects of landiolol hydrochloride on prevention of atrial fibrillation and on hemodynamics in the acute postoperative phase after heart valve surgery. The subjects were 60 patients who underwent valve surgery at our hospital from April 2008 to July 2010. The patients were randomly divided into two groups: the landiolol group (30 patients) and the control (no landiolol) group (30 patients). In the landiolol group, continuous intravenous landiolol was initiated immediately on admission to the intensive care unit at a dose of 10 μg/kg/ minute. Occurrence of atrial fibrillation was compared between the groups over an observation period of 72 hours after surgery. Atrial fibrillation occurred in 6 patients (20%) in the landiolol group and 16 (53.3%) in the control group during the observation period. Landiolol hydrochloride significantly reduced the occurrence of atrial fibrillation in the acute postoperative phase after heart valve surgery. Heart rate was significantly decreased by landiolol, but aggravation of hemodynamics was not observed. These results suggest that landiolol is a useful drug for prevention of atrial fibrillation after valve surgery.

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The prognostic value of parameters derived from a cardiopulmonary exercise test (CPET) is well established in patients stabilized after acute heart failure (HF). Under multidisciplinary disease management, this study sought to test whether noninvasive cardiac output (CO) monitoring (NICOM) during the CPET provides additional prognostic value. In total, 131 patients stabilized after acute HF agreed to undergo the CPET with NICOM. Outcome follow-up focused on composite events of death and HF-related rehospitalization. Patients with a peak cardiac index (CI) of ≤ 4.5 L/minute/ m² (n = 32), compared to those with a peak CI of > 4.5 L/minute/m² (n = 99), had higher incidences of diabetes mellitus (DM) and hypertension, but had lower hemoglobin levels, estimated glomerular filtration rates (eGFR), oxygen uptake efficiency slope (OUES), and peak oxygen uptake (VO₂). During the 1.2 ± 0.7 years of follow-up, there were 8 (6.1%) deaths, and 16 (12.2%) HF-related rehospitalizations. In a Cox univariable analysis, a lower event-free survival was associated with a history of DM, a higher Ve/VCO₂ slope, lower peak VCO₂ and eGFR, and a peak CI of ≤ 4.5 L/minute/ m² (P < 0.05). The Cox multivariable analysis showed that the Ve/VCO₂ slope (hazard ratio (HR) = 1.08, 95% confidence interval (CI): 1.01~1.16, P = 0.02) and peak CI of ≤ 4.5 L/minute/m² (HR = 3.26, 95% CI: 1.18~9.01, P = 0.02) were significant independent predictors. In conclusion, NICOM during the CPET was demonstrated to provide prognostic information in addition to traditional risk factors, biomarkers, and other well-established CPET parameters.

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When pulmonary embolism (PE) develops, circulatory collapse and hypoxia are caused at the same time. The rapid and proper use of extracorporeal life support (ECLS) can improve the mortality rate of patients with collapsed massive PE. No study has examined the influence of treatment that involved adding catheter based-intervention to ECLS with massive collapsed PE. Thirty-five patients with massive PE were examined, and 10 of these patients were placed on ECLS. Eight of the 10 patients placed on ECLS for massive PE were female, and the median age was 61 years. Seven patients had in-hospital onset PE and 3 patients out-of-hospital onset PE. Their underlying conditions were a cerebral infarction (3 patients), coronary artery disease (5 patients), collagen disease (one patient), postoperative state (3 patients), and lung disease (2 patients). Pulmonary angiographic findings showed that a filling defect or complete occlusion was observed in all 10 patients in the proximal lobular arteries, 6 of which had large thrombi stretching to the main pulmonary arteries. All patients underwent thrombolysis. Percutaneous catheter embolus fragmentation and/or thrombectomy were undertaken in 7 patients. All patients required red blood cell transfusion for cannulation site bleeding. The mean duration of ECLS bypass was 48 ± 44 hours. The 30 day mortality rate was 30%. The current study clarified the characteristics of patients with massive PE requiring ECLS. These patients have extensive pulmonary thromboemboli, thus, the aggressive use of catheter-based intervention appears to have beneficial effects for massive PE requiring ECLS.

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Catheter ablation of persistent/long-persistent atrial fibrillation (AF) has been shown to be less effective by pulmonary vein isolation (PVI) and additional left atrial (LA) complex fractionated atrial electrograms and long linear lesions are often required. Recent reports have demonstrated right atrial (RA) ablation increases the success rate of maintaining sinus rhythm in persistent/long-persistent AF. The aim of this study was to investigate whether effective RA linear lesions can terminate AF and render it noninducible in a canine model of rapid atrial pacing-induced sustained AF. Sustained AF was induced by rapid atrial pacing in 20 dogs. AF duration was 21-126 days (median, 50 days). Four RA linear lesions (superior vena cava-inferior vena cava, septal line, transverse line, and cavo-tricuspid line) were created with the use of 1 of 3 different ablation catheters (large-tip [8-mm tip], coil-tip, and cooled-tip catheters). AF was terminated with the large-tip catheter in 4/7 dogs (1 dog died of ventricular fibrillation [VF]), with the coil-tip catheter in 3/7 dogs (1 dog died of VF), and with the cooled-tip catheter in 1/6 dogs. In 6 dogs in which AF could not be terminated acutely by RA ablation, AF terminated spontaneously at 7-78 days (median, 14 days) after ablation. RA linear ablation terminated AF with limited success in our dog model of rapid atrial pacing-induced AF, but late AF termination was noted in the surviving dogs. Therefore, RA linear lesions in addition to the PVI and LA lesions may have additional effects on the catheter ablation for the persistent AF.

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Mitochondrial disorders comprise a heterogeneous group of diseases with multisystem involvement including myocardium. Most cases of mitochondrial cardiomyopathy are associated with myopathy and encephalopathy and are generally present in infancy or childhood. The disease often exhibits a rapid downward course with death frequently occuring within the first year of life. We describe a unique case of hypertrophic cardiomyopathy due to mitochondrial DNA mutation m.3303C >T in the MT-TL1 gene, diagnosed accidentally in a 35-year-old male. The patient initially presented with stroke of assumed cardioembolic origin due to the presence of two interatrial communications associated with mobile aneurysm of the interatrial septum. No other extracardiac manifestations of mitochondrial disorder were observed.

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A 60-year-old man with severe heart failure underwent an orthotopic heart transplant. Maintenance immunosuppression consisted of a calcineurin inhibitor, mycophenolate mofetil (MMF), and a glucocorticoid. Six months after the transplantation, coronary angiography (CAG) and intravascular ultrasound sonography (IVUS) showed rapidly progressive cardiac allograft vasculopathy (CAV) along with acute cellular rejection. Methylprednisone pulse therapy resulted in the resolution of acute rejection. MMF was exchanged for everolimus (EVL) and 6 months after EVL therapy, CAG and IVUS revealed the regression of CAV. EVL can improve established CAV as well as prevent the progression of CAV.

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Hypervolemic hyponatremia is often complicated with advanced heart failure together with increased excretion of sodium by diuretics. Tolvaptan, an oral vasopressin-2-receptor antagonist, has been previously reported to improve congestion and correct hyponatremia through increased excretion of free water. However, there is little evidence concerning the administration of tolvaptan in patients with stage D heart failure. We experienced 2 patients with stage D heart failure who received 3.75 mg/day of tolvaptan to correct hyponatremia before ventricular assist device implantation. It may be useful, even for patients with stage D heart failure, to administer a low dose of tolvaptan to treat hyponatremia before ventricular assist device implantation to avoid a drastic alteration in serum sodium concentration perioperatively.

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There have been only a few reports regarding the relation between snow shoveling and acute heart failure syndromes (AHFS). We present a case series of 5 patients who presented with AHFS, all within 5 days after shoveling snow. Although all patients underwent examination at a regular out-patient clinic, no patient had prior signs or symptoms of heart failure. The condition of all patients had gradually deteriorated, with no abrupt onset of dyspnea after shoveling snow. Four of the 5 patients demonstrated a preserved ejection fraction on echocardiography. Snow shoveling may lead to AHFS in patients who are at risk for developing heart failure.

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