215 resultados para ventricular arrhythmias
Resumo:
BACKGROUND: Resistance training (RT) is safe and practicable in low-risk populations with coronary artery disease. In patients with left ventricular (LV) dysfunction after an acute ischaemic event, few data exist about the impact of RT on LV remodelling. METHODS: In this prospective, randomized, controlled study, 38 patients, after a first myocardial infarction and a maximum ejection fraction (EF) of 45%, were assigned either to combined endurance training (ET)/RT (n=17; 15 men; 54.7+/-9.4 years and EF: 40.3+/-4.5%) or to ET alone (n=21; 17 men; 57.0+/-9.6 years and EF: 41.9+/-4.9%) for 12 weeks. ET was effectuated at an intensity of 70-85% of peak heart rate; RT, between 40 and 60% of the one-repetition maximum. LV remodelling was assessed by MRI. RESULTS: No statistically significant differences between the groups in the changes of end-diastolic volume (P=0.914), LV mass (P=0.885) and EF (P=0.763) were observed. Over 1 year, the end-diastolic volume increased from 206+/-41 to 210+/-48 ml (P=0.379) vs. 183+/-44 to 186+/-52 ml (P=0.586); LV mass from 149+/-28 to 155+/-31 g (P=0.408) vs. 144+/-36 to 149+/-42 g (P=0.227) and EF from 49.1+/-12.3 to 49.3+/-12.0% (P=0.959) vs. 51.5+/-13.1 to 54.1% (P=0.463), in the ET/RT and ET groups, respectively. Peak VO2 and muscle strength increased significantly in both groups, but no difference between the groups was noticed. CONCLUSION: RT with an intensity of up to 60% of the one-repetition maximum, after an acute myocardial infarction, does not lead to a more pronounced LV dilatation than ET alone. A combined ET/RT, or ET alone, for 3 months can both increase the peak VO2 and muscle strength significantly.
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Cardiogenic shock complicates up to 7% of ST-segment elevation myocardial infarctions and 2.5% of non-ST-segment elevation myocardial infarctions, with an associated mortality of 50% to 70%. Primary cardiac pump failure is followed by secondary vital organ hypoperfusion and subsequent activation of various cascade pathways, resulting in a downward spiral leading to multiple organ failure and, ultimately, death. Immediate restoration of cardiac output by means of percutaneous ventricular assist devices restores hemodynamic -stability and is an important advance in the management of patients with severe left ventricular dysfunction and cardiogenic shock. This article reviews available evidence supporting the use of percutaneous ventricular assist devices in patients suffering from cardiogenic shock.
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AIMS: Multiple arrhythmia re-inductions were recently shown in His-Purkinje system (HPS) ventricular tachycardia (VT). We hypothesized that HPS VT was a frequent mechanism of repetitive or incessant VT and assessed diagnostic criteria to select patients likely to have HPS VT. METHODS AND RESULTS: Consecutive patients with clustering VT episodes (>3 sustained monomorphic VT within 2 weeks) were included in the analysis. HPS VT was considered plausible in patients with (i) impaired left ventricular function associated with dilated cardiomyopathy or valvular heart disease; or (ii) ECG during VT similar to sinus rhythm QRS or to bundle-branch block QRS. HPS VT was plausible in 12 of 48 patients and HPS VT was demonstrated in 6 of 12 patients (50%, or 13% of the whole study group). Median VT cycle length was 318 ms (250-550). Catheter ablation was successful in all six patients. CONCLUSION: His-Purkinje system VT is found in a significant number of patients with repetitive or incessant VT episodes, and in a large proportion of patients with predefined clinical or electrocardiographic characteristics. Since it is easily amenable to catheter ablation, our data support the screening of all patients with repetitive VT in this regard and an invasive approach in a selected group of patients.
Resumo:
BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an important cause of sudden death in young adults. On the basis of histopathological findings its pathogenesis may involve both a genetic origin and an inflammatory process. Bartonella henselae may cause endomyocarditis and was detected in myocardium from a young male who succumbed to sudden cardiac death. HYPOTHESIS: We hypothesized that chronic infection with Bartonella henselae could contribute to the pathogenesis of ARVC. METHODS: We investigated sera from 49 patients with ARVC for IgG antibodies to Bartonella henselae. In this study, 58 Swiss blood donors tested by the same method served as controls. RESULTS: Six patients with ARVC (12%) had positive (>1:256) IgG titres in the immunofluorescence test with Bartonella henselae. In contrast, only 1 elevated titre was found in 58 controls (p < or = 0.05). Interestingly, all patients with increased titres had no familial occurrence of ARVC. CONCLUSIONS: Further studies in larger patient cohorts seem justified to investigate a possible causal link between chronic Bartonella henselae and ARVC, in particular its sporadic (nonfamilial) form.
Resumo:
Few data exist on the incidence of spontaneously occurring ventricular tachycardia (VT) in an unselected pediatric population. The aim of this study was to define the incidence and outcomes of VT in a general pediatric population. A retrospective analysis was performed of all documented episodes of VT in children referred to a single center during a 10-year study period ending in December 2005. The study center drains a stable referral area with 252,000 children aged <16 years, with no other pediatric cardiologic or pediatric intensive care services available. Twenty-seven patients with spontaneously occurring episodes of VT were observed, accounting for a VT incidence of 1.1 episodes/100,000 childhood years. Thirteen patients had VT in the absence of structural heart disease, and 14 had VT in the presence of a wide range of underlying cardiac disease. Overall mortality was 5 of 27 patients (19%), but mortality was seen exclusively in patients with underlying heart disease; for this subgroup of patients, mortality was 36%. Idiopathic VT in children with structurally normal hearts carried a good prognosis, and treatment was required in a minority (20%) of these patients. In conclusion, this study highlights that VT in childhood is rare, and outcomes are highly dependent on the underlying pathologic substrate.
Resumo:
A 19-year-old man suffered a cardiac arrest during a promenade with his friends. Cardiac resuscitation was started immediately. Anamnesis uncovered that the father as well as a cousin of the patient suffered from myotonic dystrophy (MD). Follow-up ECG monitoring showed intercurrent III degree AV-block as well as several asymptomatic episodes of ventricular tachycardias, atrial flutter with changing conduction and atrial fibrillation. Neuromuscular testing and genetic analyses confirmed the diagnosis of a myotonic dystrophy. Myotonic dystrophy (MD) is a chronic, slowly progressing, autosomal dominant inherited multisystemic disease.The clinical presentation is characterized by wasting of the muscles with delayed relaxation, cataracts and endocrine changes. MD is associated with both cardiac conduction disturbances and structural heart abnormalities. Electrocardiographic abnormalities include conduction disturbances or tachyarrhythmias. This case illustrates that potentially lethal arrhythmias inducing sudden cardiac death may occur in MD patients even in the absence of neurologic symptoms characterizing the systemic illness.
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A 83-year-old woman underwent percutaneous closure of postinfarction ventricular septal defect following anteroseptal myocardial infarction and percutaneous coronary intervention with stent implantation of the left anterior descending coronary artery. Postinfarction percutaneous ventricular septal defect closure was initially complicated by an iatrogenic left ventricular free-wall perforation. Both defects were closed using two Amplatzer muscular VSD occluders during the same session.
Resumo:
Despite the growing recognition of the patent foramen ovale (PFO), particularly when associated with an atrial septal aneurysm, as risk factor for several disease manifestations (above all paradoxical embolism), the optimal treatment strategy for symptomatic patients remains controversial. Percutaneous PFO closure is a minimally invasive procedure which can be performed with high success and low morbidity. For secondary prevention of recurrent embolic events, it appears to be clinically at least as effective as oral anticoagulation. Ventricular septal defects (VSDs) are the most common congenital heart defects. Percutaneous VSD closure is more intricate than PFO closure. It is associated with a significant risk of both peri-interventional and mid-term complications. In suitable patients with congenital VSD, device closure may well be the preferred treatment both for muscular or perimembranous VSDs and for residual defects after surgical VSD closure. The risk of complete atrioventricular conduction block remains a concern in the perimembranous group. The history, technique and clinical role of percutaneous PFO and VSD closure are discussed, with emphasis on current problems and future developments.
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Left ventricular assist devices were developed to support the function of a failing left ventricle. Owing to recent technological improvements, ventricular assist devices can be placed by percutaneous implantation techniques, which offer the advantage of fast implantation in the setting of acute left ventricular failure. This article reviews the growing evidence supporting the clinical use of left ventricular assist devices. Specifically, we discuss the use of left ventricular assist devices in patients with cardiogenic shock, in patients with acute ST-elevation myocardial infarction without shock, and during high-risk percutaneous coronary interventions.
Resumo:
BACKGROUND: The aortomitral continuity (AMC) has been described as a site of origin for ventricular tachycardias (VT) in structurally normal hearts. There is a paucity of data on the contribution of this region to VTs in patients with structural heart disease. METHODS AND RESULTS: Data from 550 consecutive patients undergoing catheter ablation for VT associated with structural heart disease were reviewed. Twenty-one (3.8%) had a VT involving the peri-AMC region (age, 62.7+/-11 years; median left ventricular ejection fraction, 43.6+/-17%). Structural heart disease was ischemic in 7 (33%), dilated cardiomyopathy in 10 (47.6%), and valvular cardiomyopathy in 4 (19%) patients, respectively. After 1.9+/-0.8 catheter ablation procedures (including 3 transcoronary ethanol ablations) the peri-AMC VT was not inducible in 19 patients. The remaining 2 patients underwent cryosurgical ablation. Our first catheter ablation procedure was less often successful (66.7%) for peri-AMC VTs compared with that for 246 VTs originating from the LV free wall (81.4%, P=0.03). During a mean follow-up of 1.9+/-2.1 years, 12 (57.1%) patients remained free of VT, peri-AMC VT recurred in 7 patients, and 1 patient had recurrent VT from a remote location. Three patients died. Analysis of 50 normal coronary angiograms demonstrated an early septal branch supplying the peri-AMC area in 58% of cases that is a potential target for ethanol ablation. CONCLUSIONS: VTs involving the peri-AMC region occur in patients with structural heart disease and appear to be more difficult to ablate compared with VTs originating from the free LV wall. This region provides unique challenges for radiofrequency ablation, but cryosurgery and transcoronary alcohol ablation appear feasible in some cases.
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BACKGROUND: Currently, only anecdotal information exists on the presentation and outcome of coronary arterial injury after ablation procedures. METHODS AND RESULTS: Four patients who sustained coronary artery injury of a cohort of patients undergoing 4655 consecutive ablation procedures (0.09%) are described. The patients' mean age was 45+/-11 years, and 1.8+/-0.5 prior ablation attempts had been unsuccessful. Coronary injury occurred from epicardial ventricular tachycardia ablation in 2 patients (irrigated radiofrequency ablation in one and cryoablation in the other) and ablation within the middle cardiac vein with irrigated radiofrequency in 2 patients. All involved branches of the right coronary artery. Acute occlusion presenting with ST-segment elevation immediately after ablation was recognized during the procedure in 2 cases. Occlusion failed to respond to nitroglycerin or balloon dilation, and stenting was required in both cases. Acute myocardial infarction occurred 2 weeks after epicardial ablation as a result of occlusion of a right ventricular branch of the right coronary artery giving rise to the posterior descending coronary artery in 1 patient. A moderate asymptomatic stenosis was seen on angiography after epicardial cryoablation in 1 patient. All patients recovered and remained asymptomatic from the coronary injury and arrhythmias during 37+/-53 months of follow-up. CONCLUSIONS: Coronary arterial injury after ablation procedures is rare. It may present acutely or several weeks after an ablation procedure. Acute occlusion appears to require coronary stenting. Unanticipated anatomic variations can predispose to coronary injury.
Resumo:
BACKGROUND: Due to better early and long-term outcome, the increasing population of grown-ups with congenital heart disease (GUCH) brings up unexpected quality of life (QoL) issues. The cardiac lesion by itself is not always the major problem for these patients, since issues pertaining to QoL and psychosocial aspects often predominate. This study analyses the QoL of GUCH patients after cardiac surgery and the possible impact of medical and psychosocial complications. PATIENTS AND METHODS: A questionnaire package containing the SF-36 health survey (health related QoL), the HADS test (anxiety/depression aspects) and an additional disease specific questionnaire was sent to 345 patients (mean 26+/-11 years) operated for isolated transposition of the great arteries (TGA), tetralogy of Fallot (TOF), and ventricular septal defect (VSD). The scores were compared with age- and gender-matched standard population data and in relation to the underlying congenital heart disease (CHD). RESULTS: In all SF-36 and HADS health dimensions the GUCH patients showed excellent scores (116+/-20), which are comparable to the standard population (100+/-15), regardless of the initial CHD (p=0.12). Eighty-two percent of the patients were found to be in NYHA class I and 83% patients declared that they do not consider their QoL to be limited by their malformation. Complications like reoperations (p=0.21) and arrhythmias (p=0.10) do not show significant impact on the QoL. The additional questionnaire revealed that 76% of adult patients have a fulltime job, 18% receive a full or partial disability pension, 21% reported problems with insurances, most of them regarding health insurances (67%), and 4.4% of adult patients declared to have renounced the idea of having children due to their cardiac malformation. CONCLUSION: QoL in GUCH patients following surgical repair of isolated TOF, TGA and VSD is excellent and comparable to standard population, this without significant difference between the diagnosis groups. However, these patients are exposed to a high rate of complications and special psychosocial problems, which are not assessed by standardized questionnaires, such as the SF-36 and HADS. These findings highlight the great importance for a multidisciplinary and specialized follow-up for an adequate management of these complex patients.