RESUMO
Assessment of the left ventricular ejection fraction plays a key role in the echocardiographic diagnosis of heart failure. The parameter most commonly used is the ejection fraction computed with the biplane disc summation method of Simpson; however, there are numerous limitations to this method, such as the assumption of geometrical symmetry, a substantial intraobserver and interobserver variability, foreshortening of the left ventricle and insufficient image quality for endocardial tracking. Alternative parameters for the evaluation of left ventricular function should be taken into consideration. Speckle tracking echocardiography has proven to be a reliable prognostic factor and a good tool for differentiating cardiomyopathies. Simple measurements, which are also feasible with poor image quality, are mitral annular plane systolic excursion (MAPSE) and the velocity of mitral annular movement (Sm or S'). In mitral regurgitation, left ventricular dP/dt represents the time to build up a certain pressure gradient and is therefore a measure of the contractile force exerted. Three-dimensional echocardiography has proven to be an important tool not only for three-dimensional measurement of the left ventricular ejection fraction but also for multivectoral speckle tracking analysis.
Assuntos
Ecocardiografia Tridimensional/métodos , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/fisiopatologia , Volume Sistólico , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/fisiopatologia , Algoritmos , Técnicas de Imagem por Elasticidade/métodos , Insuficiência Cardíaca/complicações , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Disfunção Ventricular Esquerda/etiologiaRESUMO
Heart failure with preserved ejection fraction (HFpEF) is highly prevalent in patients on maintenance haemodialysis (HD) and lacks effective treatment. We investigated the effect of spironolactone on cardiac structure and function with a specific focus on diastolic function parameters. The MiREnDa trial examined the effect of 50 mg spironolactone once daily versus placebo on left ventricular mass index (LVMi) among 97 HD patients during 40 weeks of treatment. In this echocardiographic substudy, diastolic function was assessed using predefined structural and functional parameters including E/e'. Changes in the frequency of HFpEF were analysed using the comprehensive 'HFA-PEFF score'. Complete echocardiographic assessment was available in 65 individuals (59.5 ± 13.0 years, 21.5% female) with preserved left ventricular ejection fraction (LVEF > 50%). At baseline, mean E/e' was 15.2 ± 7.8 and 37 (56.9%) patients fulfilled the criteria of HFpEF according to the HFA-PEFF score. There was no significant difference in mean change of E/e' between the spironolactone group and the placebo group (+ 0.93 ± 5.39 vs. + 1.52 ± 5.94, p = 0.68) or in mean change of left atrial volume index (LAVi) (1.9 ± 12.3 ml/m2 vs. 1.7 ± 14.1 ml/m2, p = 0.89). Furthermore, spironolactone had no significant effect on mean change in LVMi (+ 0.8 ± 14.2 g/m2 vs. + 2.7 ± 15.9 g/m2; p = 0.72) or NT-proBNP (p = 0.96). Treatment with spironolactone did not alter HFA-PEFF score class compared with placebo (p = 0.63). Treatment with 50 mg of spironolactone for 40 weeks had no significant effect on diastolic function parameters in HD patients.The trial has been registered at clinicaltrials.gov (NCT01691053; first posted Sep. 24, 2012).
Assuntos
Insuficiência Cardíaca , Espironolactona , Idoso , Feminino , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Diálise Renal , Volume Sistólico , Função Ventricular EsquerdaRESUMO
Occasional patients have excessive defibrillation energy requirements despite appropriate transvenous defibrillation lead position and the use of biphasic shocks. A single-element subcutaneous array electrode was implanted in 2 patients with a high defibrillation threshold. The array electrode was implanted through the same infraclavicular incision that was used for implantation of the transvenous lead. The defibrillation threshold decreased from 30 J to 15 J and from 24 J to 9 J with the subcutaneous array electrode.
Assuntos
Desfibriladores Implantáveis , Cardiomiopatia Dilatada/terapia , Eletrodos Implantados , Humanos , Masculino , Pessoa de Meia-Idade , Desenho de PróteseRESUMO
The patch electrode and the array electrode are the two types of subcutaneous leads available as an adjunct to a transvenous lead system in patients with high defibrillation thresholds. A prospective randomized study was conducted in 30 consecutive patients comparing the efficacy and the long-term performance of a patch electrode with an array electrode. After determination of the defibrillation threshold for the transvenous lead alone, a subcutaneous patch or an array electrode was implanted in random order. Adding a patch electrode decreased the defibrillation threshold in seven out of 15 patients (47%) from 13.2+/-6.6 to 10.5+/-5.1 J (P<0.05). In 13 out of 15 patients (87%), the implantation of an array electrode caused a significant lowering of the defibrillation threshold from 15.4+/-6.6 to 8.2+/-5.0 J (P<0.0001). The array electrode was significantly more effective in lowering the defibrillation threshold than the patch electrode (P<0.01). Complications during follow-up associated with the subcutaneous patch electrode were observed in four patients whereas no complications were associated with the array electrode (P<0.01). The additional implantation of an array electrode is more effective and associated with fewer complications compared to a patch electrode.
Assuntos
Desfibriladores Implantáveis , Cardioversão Elétrica/instrumentação , Eletrodos Implantados , Taquicardia Ventricular/terapia , Fibrilação Ventricular/terapia , Adulto , Idoso , Análise de Variância , Impedância Elétrica , Desenho de Equipamento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Taquicardia Ventricular/fisiopatologia , Fibrilação Ventricular/fisiopatologiaRESUMO
AIM OF THE STUDY: It is generally accepted that chronic therapy with antiarrhythmic drugs might increase the defibrillation threshold at implantation of an implantable cardioverter defibrillator. A recently published animal study showed a minor effect of the class 1 antiarrhythmic drug lidocaine on the defibrillation threshold if biphasic shocks were used. METHODS AND RESULTS: We therefore performed a retrospective analysis in 89 patients who received an ICD capable of monophasic (n=18) or biphasic (n=71) shocks with a transvenous lead system. In all patients the defibrillation threshold was determined according to the same step down protocol. In the 18 patients with a monophasic device the effects of chronic therapy with amiodarone (n=7) on the defibrillation threshold were evaluated in comparison to a group without antiarrhythmic treatment (n=11). In those patients receiving a biphasic device the effects of chronic therapy with amiodarone (n=29), sotalol (n=20) or no antiarrhythmic medication (n=22) on the defibrillation threshold were evaluated. The groups receiving a monophasic device did not differ in respect to age, sex, underlying cardiac disease, clinical arrhythmia (VT/VF), clinical functional status, left ventricular ejection fraction and the number of patients with additional subcutaneous electrodes. These parameters as well as the type of implanted device were not different between patient groups receiving a biphasic device. Patients on chronic amiodarone therapy receiving a monophasic device had a significantly higher defibrillation threshold (29.1 +/- 8.8 J) than patients without antiarrhythmic treatment (19.1 +/- 5.1 J, P = 0.021). The groups did not differ significantly in respect to the impedance measured at the shocking lead (P = 0.13). In three patients on chronic amiodarone an epicardiac lead system had to be implanted due to an inadequate monophasic defibrillation threshold compared to no patient without antiarrhythmic drug treatment (P = 0.043). In the patients with a biphasic device the intraoperative defibrillation threshold was not significantly different between the three study groups (P = 0.44). No patient received an epicardiac lead system. The defibrillation threshold in the amiodarone group was 15.3 +/- 7.3 J, in the sotalol group 14.4 +/- 7.2 J and in the patients without antiarrhythmic drug treatment 17 +/- 6.1 J. As well, no significant difference was seen between the groups in respect of the impedance of the high voltage electrode (P = 0.2). CONCLUSION: With the use of a biphasic device in combination with a transvenous lead system the intraoperative defibrillation threshold is not significantly different between patients on chronic amiodarone in comparison to patients without antiarrhythmic drug treatment or patients on chronic oral sotalol. This is in contrast to our findings with a monophasic device.
Assuntos
Amiodarona/farmacologia , Antiarrítmicos/farmacologia , Desfibriladores Implantáveis , Sistema de Condução Cardíaco/efeitos dos fármacos , Sotalol/farmacologia , Idoso , Arritmias Cardíacas/tratamento farmacológico , Arritmias Cardíacas/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos RetrospectivosRESUMO
21 patients with left-sided idiopathic varicoceles were examined by angiodynography, Doppler sonography and phlebography. Patients treated by sclerosis therapy were re-examined by angiodynography and Doppler sonography after six weeks. Both methods permitted classification into a "stop & shunt type". Angiodynography, particularly for small varicoceles, was quicker and more pleasant for the patient. Real time imaging by angiodynography makes it possible to evaluate pre- and posttherapeutic changes in the pampiniform plexus and in the scrotum.
Assuntos
Ultrassonografia , Varicocele/diagnóstico , Adolescente , Adulto , Criança , Cor , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Flebografia , Estudos Prospectivos , Soluções Esclerosantes/uso terapêutico , Testículo/irrigação sanguínea , Testículo/patologia , Ultrassonografia/instrumentação , Ultrassonografia/métodos , Manobra de Valsalva , Varicocele/terapia , VeiasRESUMO
Biventricular pacing for cardiac resynchronization is a promising therapy for symptomatic improvement in selected patients with underlying severe congestive heart failure. ICD treatment has been shown to prolong life in patients with life threatening ventricular tachyarrhythmias, but it does not improve quality of life. This review discusses current experience with ICD's incorporating biventricular pacing.
Assuntos
Desfibriladores Implantáveis , Insuficiência Cardíaca/terapia , Ventrículos do Coração/cirurgia , Marca-Passo Artificial , Arritmias Cardíacas/complicações , Insuficiência Cardíaca/etiologia , HumanosAssuntos
Doenças do Colágeno/diagnóstico , Atrofia Óptica/diagnóstico , Neurite Óptica/diagnóstico , Doença de Raynaud/diagnóstico , Transtornos da Visão/diagnóstico , Adulto , Anticorpos Antinucleares/sangue , Doenças do Colágeno/tratamento farmacológico , Ciclofosfamida/administração & dosagem , Diagnóstico Diferencial , Quimioterapia Combinada , Feminino , Angiofluoresceinografia , Humanos , Imunossupressores/administração & dosagem , Atrofia Óptica/tratamento farmacológico , Neurite Óptica/tratamento farmacológico , Prednisolona/administração & dosagem , Doença de Raynaud/tratamento farmacológico , Síndrome de Sneddon/diagnóstico , Síndrome de Sneddon/tratamento farmacológico , Transtornos da Visão/tratamento farmacológico , Campos VisuaisAssuntos
Desfibriladores Implantáveis/efeitos adversos , Eletrodos Implantados/efeitos adversos , Marca-Passo Artificial/efeitos adversos , Pneumotórax/diagnóstico por imagem , Pneumotórax/etiologia , Radiografia Torácica/métodos , Desfibriladores Implantáveis/classificação , Eletrodos Implantados/classificação , Desenho de Equipamento , Falha de Equipamento , Análise de Falha de Equipamento/métodos , Humanos , Marca-Passo Artificial/classificação , Implantação de Prótese/efeitos adversos , Implantação de Prótese/métodosRESUMO
Cardiac resynchronization therapy is recommended in patients with advanced heart failure (usually NYHA class III or IV) despite optimal pharmacologic therapy, severe systolic dysfunction (eg, left ventricular ejection fraction < 35 percent) and intraventricular conduction delay or echocardiographic indices of dyssynchrony and wide QRS complex (eg, QRS > or = 120 ms). Viral infection is the most common cause of myocarditis and has been implicated in the development of non-ischemic cardiomyopathy. We report on a patient who developed progressive congestive heart failure caused by non-ischemic cardiomyopathy after liver transplantation and reactivation of the underlying hepatitis C. Due to an insufficient response to optimized pharmacological therapy, the patient was successfully treated using cardiac resynchronization therapy.
Assuntos
Cardioversão Elétrica , Insuficiência Cardíaca/terapia , Cateterismo Cardíaco , Cardiomiopatia Dilatada/complicações , Cardiomiopatia Dilatada/etiologia , Angiografia Coronária , Ecocardiografia , Eletrocardiografia , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/etiologia , Hepatite C Crônica/complicações , Hepatite C Crônica/cirurgia , Humanos , Transplante de Fígado/efeitos adversos , Masculino , Pessoa de Meia-IdadeRESUMO
BACKGROUND: The compelling safety and efficacy data in numerous large, blinded trials on adult patients, and the progress in device- and leadtechnology have led to increasing use of implantable cardioverter defibrillators in pediatric patients. The purpose of our study was to assess the efficacy and safety of ICD in the pediatric age group of a tertiary referral centre. PATIENTS AND METHODS: Between March 1998 and October 2003 12 patients underwent ICD-implantation. The mean age at implantation was 14,8 years with a range between 10-17 years. The underlying cardiac disorders included long QT-syndrome in 4 patients, ventricular fibrillation in 3 patients, dilated cardiomyopathy in 4 patients, and congenital heart disease in 1 patient (pulmonary atresia with ventricular septal defect after Rastelli repair). All patients received a transvenous ICD-system (VVI-ICD in 4 patients, DDD-ICD in 8 patients). RESULTS: The mean follow up was 35 months (6-68 months). During this period there were no severe complications nor mortality. We haven't seen infections, thromboembolic complications or lead-perforations. 2 patients (17 %) received appropriate DC-shocks, 1 patient (8 %) received an inappropriate DC-shock. 10 patients (83 %) had no malignant ventricular arrhythmia under medical therapy. 2 patients (17 %) required revision because of lead-dysfunction. In 2 patients with DCM the device was explanted during orthotopic heart transplantation. CONCLUSIONS: Our data demonstrate that advances in device- and leadtechnology have resulted in a decrease of severe complications in the pediatric age group. We conclude that ICD-implantation represents a safe and effective therapy for children and adolescents with lifethreatening ventricular dysrhythmias. Since it represents an invasive therapy, indication should be confined to patients with lifethreatening dysrhythmias according to the guidelines of the American Heart Association.
Assuntos
Cardiomiopatia Dilatada/terapia , Desfibriladores Implantáveis , Cardiopatias Congênitas/terapia , Síndrome do QT Longo/terapia , Fibrilação Ventricular/terapia , Adolescente , Criança , Eletrocardiografia , Falha de Equipamento , Segurança de Equipamentos , Feminino , Seguimentos , Humanos , Masculino , Resultado do TratamentoRESUMO
On 99 testes of corpses (death had occurred between 26 und 86 years) comparative volumetry was done. In the left surrounding capsules (without scrotal skin and tunica dartos) the testes were measured via real time sonography in a waterbath (7.5 MHz linear-scan), afterwards length, breadth and height were measured by a sliding calibre, the largest diameter (the length) of the testis was determined by Schirren's circle and finally the size of the testis was measured via Prader's orchidometer. After all the testes were surgically exposed, their volume (by litres) was determined according to Archimedes' principle. As for the Archimedes' principle a random mean error of 7% must be accepted, sonographic determination of the volume showed a random mean error of 15%. Whereas the accuracy of measurement increases with increasing volumes, both methods should be used with caution if the volumes are below 4 ml, since the possibilities of error are rather great. According to Prader's orchidometer the measured volumes on average were higher (+ 27%) with a random mean error of 19.5%. With Schirren's circle the obtained mean value was even higher (+ 52%) in comparison to the "real" volume by Archimedes' principle with a random mean error of 19%. The measurements of the testes in the left capsules by sliding calibre can be optimized, if one applies a correcting factor f (sliding calibre) = 0.39 for calculation of the testis volume corresponding to an ellipsoid. Here you will get the same mean value as in Archimedes' principle with a standard mean error of only 9%. If one applies the correction factor of real time sonography of testis f (sono) = 0.65 the mean value of sliding calibre measurements would be 68.8% too high with a standard mean error of 20.3%. For measurements via sliding calibre the calculation of the testis volume corresponding to an ellipsoid one should apply the smaller factor f (sliding calibre) = 0.39, because in this way the left capsules of testis and the epididymis are considered.
Assuntos
Testículo/anatomia & histologia , Adolescente , Adulto , Idoso , Envelhecimento , Criança , Pré-Escolar , Humanos , Masculino , Métodos , Pessoa de Meia-Idade , Testículo/crescimento & desenvolvimento , Testículo/patologia , UltrassomRESUMO
99 testes of corpses (death had occurred between 26 and 86 years) were examined via real time sonography in a water-bath, measuring their length, breadth and height. They were then exposed surgically and their volume (by litres) determined according to Archimedes' principle. The volume determined via testes sonography was set in relationship to the "real" volume according to Archimedes. A correction factor was found (corresponding to an ellipsoid) of f (sono) = 0.65 +/- 0.1 (for the rotation ellipsoid this is pi/6 = 0.524). On multiplication with the optimised factor f (sono) = 0.65 the best possible calculated testes volume was obtained. A direct comparison of both measurement methods showed a random mean error of 7% for the principle of Archimedes, whereas with sonographic determination of the volume a mean error of 15% must be taken into account. Whereas the accuracy of measurement increases with increasing volumes, both methods should be used with caution if the volumes are below 4 ml, since the possibilities of error are rather great.
Assuntos
Testículo/patologia , Ultrassonografia , Adulto , Idoso , Idoso de 80 Anos ou mais , Humanos , Masculino , Pessoa de Meia-Idade , Valores de ReferênciaRESUMO
X-ray contrast imaging of the urethra, retrograde as urethrogram (UG) or antegrade as part of the miction cystourethrogram (MCU), has proved successful as a standard examination in urological diagnosis. The article presents a sonography technique enabling three-dimensional morphological and functional imaging the entire male urethra by real-time sonography. Advantages over x-ray film methods are the repeatability at any time, low invasiveness, absence of exposure to x-rays, and lesions of the urethral mucosa by catheters, as well as the avoidance of iodine-induced contrast medium reactions. Miction urethrosonography (MUS) is suitable for screening diagnosis of urethral stricture in miction difficulties, for excluding an iatrogenic of congenital urethral diverticulum, and for control after urethral surgery (internal urethrotomy, urethroplasty).
Assuntos
Ultrassonografia , Estreitamento Uretral/diagnóstico , Urodinâmica , Urografia , Adulto , Divertículo/diagnóstico , Humanos , Masculino , Ultrassonografia/instrumentação , Uretra/patologia , Doenças Uretrais/diagnóstico , Urografia/instrumentaçãoRESUMO
A 62-year-old male patient with coronary artery disease and drug refractory sustained ventricular tachycardia received an implantable cardioverter defibrillator (PRX III, model 1720, CPI) with a transvenous lead system (Endotak, model 0115, CPI) in combination with a subcutaneous array electrode (SQ array, model 049, CPI). The intraoperative defibrillation threshold was 15 J and was confirmed 1 week later at the hospital discharge test. Three months after discharge from hospital the patient reported 5 shocks during moderate physical exertion followed by a tachycardia associated with dizziness which terminated spontaneously. The print out of the stored electrogram showed a supraventricular tachycardia (probably sinus tachycardia) with a heart rate of 154/min which activated the device. Antitachycardia pacing did not terminate the supraventricular tachycardia, and hence shock therapy was delivered. The first shock (34 J) converted the supraventricular tachycardia to a ventricular tachycardia with a heart rate of 178/min, which was not terminated by four consecutive 34 J DC shocks. There was no hint of a device or lead failure. Determination of the defibrillation threshold reconfirmed the 15 J value for termination of ventricular fibrillation. However, neither a 1 J shock nor a 34 J shock terminated a monomorphic sustained ventricular tachycardia (cycle length 340 ms) induced by noninvasive programmed electrical stimulation. The ventricular tachycardia was, however, reproducibly terminate by antitachycardia pacing. It is concluded that an inappropriate high-energy DC shock might induce a sustained ventricular tachycardia. However, a sufficient defibrillation threshold for the termination of ventricular fibrillation does not necessarily mean that a sustained ventricular tachycardia will be terminated by a high-energy DC shock.
Assuntos
Doença das Coronárias/terapia , Desfibriladores Implantáveis , Taquicardia Ventricular/terapia , Doença das Coronárias/fisiopatologia , Cardioversão Elétrica , Eletrocardiografia/instrumentação , Sistema de Condução Cardíaco/fisiopatologia , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Processamento de Sinais Assistido por Computador , Software , Taquicardia Sinusal/fisiopatologia , Taquicardia Sinusal/terapia , Taquicardia Ventricular/fisiopatologiaRESUMO
With the growing complexity of transvenous ICD-lead systems the incidence of lead complications might increase in comparison to usual pacemaker leads. The incidence of insulation defects of transvenous leads was determined during a mean follow-up time of 23.8 +/- 10.9 months. Among 130 transvenous ICD-patients, eight insulation-breaks in seven patients (6%) could be identified after a mean follow-up of 28 +/- 13 months. After a follow-up period of 12 months no lead defect was identified, after 24 months 96.3 +/- 1.8% of all transvenous leads were free of complications, after 36 months 87.9 +/- 6% and after 48 months in 61.2 +/- 18.7% of all leads no isolator fracture was found. In seven cases an operative revision was required. All insulation-defects were exclusively found in abdominally implanted silicone lead-systems type Endotak/CPI (Cardiac Pacemakers, Inc., USA): isolator fractures occurred in 12% of all Endotak leads used, 19% of the Endotak C models 62, 64, 72 and 74 were affected. In none of 66 implanted Transvene lead systems (Medtronic, Inc., USA) were isolator defects found. In six patients the proximal part of the sensing lead near the device was affected. All of these patients experienced potentially harmful repetitive device discharges. In one patient during elective ICD-replacement an isolation break of the proximal shock electrode was found, in another patient between the proximal and distal shock-electrode. Despite regular follow-ups with impedance-measurements, only in one case was the insulation break foreseeable. Stored electrograms were helpful to disclose insulation defects. With increasing age of the transvenous lead systems a growing number of insulation defects has to be expected. Especially the isolators of the first Endotak C models 60-74 seem to create major problems with increasing age.
Assuntos
Desfibriladores Implantáveis , Cardiopatias/terapia , Taquicardia Ventricular/terapia , Fibrilação Ventricular/terapia , Idoso , Eletrocardiografia Ambulatorial/instrumentação , Eletrodos Implantados , Análise de Falha de Equipamento , Feminino , Seguimentos , Cardiopatias/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Processamento de Sinais Assistido por Computador , Taquicardia Ventricular/fisiopatologia , Fibrilação Ventricular/fisiopatologiaRESUMO
Twiddler's syndrome is a rare complication in patients with pacemakers. We report this very rare syndrome in a patient with pectoral implanted unipolar cardioverter defibrillator. This syndrome was detected because the patient presented in the 3 month routine visit an exitblock with an increased pacing impedance. The defibrillation threshold remained unchanged. The chest x-ray revealed an inferolaterally migrated generator with a multiply rotated lead. The intraoperative exploration showed a generator which was rotated nine-fold around its longitudinal axis with a multiple twisted unipolar lead. The lead was substituted and the aggregate fixed with a suture to the underlying muscle fascia. An atrophy of the pectoralis muscle was found in this patient which previously resulted from a long hospital stay. This atrophy was identified as a possible risk factor for the development of Twiddler's syndrome. This report illustrates that Twiddler's syndrome, a rare complication in patients with pectoral ICD, may become a significant problem in these patients as it is for pacemaker patients but with more serious possible consequences.
Assuntos
Desfibriladores Implantáveis/efeitos adversos , Migração de Corpo Estranho/etiologia , Músculos Peitorais/patologia , Idoso , Atrofia/etiologia , Corpos Estranhos/etiologia , Humanos , Masculino , Fatores de RiscoRESUMO
INTRODUCTION: A major drawback of therapy with an implantable defibrillator is the nonspecificity of detection. Theoretically, adding atrial sensing information to a decision algorithm could improve specificity of detection. METHODS AND RESULTS: This open-label nonrandomized study compares the detection algorithm of the Ventak AV and the Ventak Mini implantable defibrillators. The Ventak AV (n = 39) uses dual chamber detection as opposed to single chamber detection (with rate stability) in the Ventak Mini (n = 55). Programmed zone configurations, rate thresholds, and stability criteria were identical in all patients. In the Ventak AV group, 235 ventricular tachyarrhythmias were adequately detected and treated by the device. In the Mini group, 699 episodes of ventricular fibrillation/tachycardia occurred. All but six of the latter episodes were correctly identified and treated: one patient with incessant ventricular tachycardia had five episodes not terminated by the device, another episode occurred in a patient with a device/lead defect. In the Ventak AV group, 33 episodes of sinus tachycardia and 166 episodes of atrial fibrillation/flutter activated the device; inappropriate therapy was applied to 41% of atrial fibrillation/flutter episodes. In the Ventak Mini group, 226 supraventricular tachyarrhythmias activated the device, eight of which were sinus tachycardia and 218 were atrial fibrillation or flutter; of the atrial fibrillation/ flutter episodes 24% were treated inappropriately (fewer vs Ventak AV, P < 0.001). CONCLUSION: The new detection algorithm incorporated in the Ventak AV did not inadvertently withhold therapy for ventricular tachyarrhythmias, but at the same time the number of inappropriate therapies for atrial fibrillation was not decreased in comparison to a single chamber device.