Dual Chamber (dual + chamber)

Distribution by Scientific Domains

Terms modified by Dual Chamber

  • dual chamber ICD
  • dual chamber pacemaker

  • Selected Abstracts

    Pacing in Right Ventricular Dysplasia after Disconnection Surgery

    Pacing in Right Ventricular Dysplasia. This report describes a 33-year-old patient with arrhythmogenic right ventricular (RV) dysplasia who had a dual chamber pacemaker implanted at age 23 years for drug-induced bradycardia. Pacing was continued after right ventricular free-wall disconnection (RVFVVD) at age 24 years. Her pacemaker was not replaced after battery depletion 7 years later. She presented the following year in severe right-sided heart failure. Her old pacemaker generator was replaced. This was followed by rapid resolution of her clinical failure and return to a full, active, physical lifestyle. This observation suggests the potential benefit of dual chamber pacing in patients with RV dysplasia after RVFWD. [source]

    A Comparison of ICD Implantations in the United States Versus Italy

    Background: The benefits conferred by implantable cardioverter defibrillators (ICDs) have expanded to primary prevention. The advancements in ICD therapy (ACT) registry in the United States and the Italian ICD registry (IIR) examine changing trends in ICD implantation in their respective countries. Data from these registries may be useful for comparison of transcontinental differences in ICD utilization. Methods: This study includes initial implantations in patients enrolled in ACT and IIR. A comparative analysis was performed for device indications based on primary or secondary prevention. Sub-group analyses by device types (single, dual chamber, or cardiac resynchronization) were performed. Results: This analysis included 4,547 primary implantations in ACT and 6,491 in IIR. The groups were similar with respect to age. There were 82% primary and 18% secondary prevention indications in ACT, versus 42% primary and 58% secondary prevention indications in IIR (P < 0.001). There was a significantly higher rate of dual chamber ICD implants in ACT than in IIR for both primary (35.7% vs 23.7%, P < 0.001) and secondary prevention (52.3% vs 36.9%, P < 0.001). Conversely, more CRT-D were implanted in IIR than in ACT (primary prevention 46.5% vs 32.0%; secondary prevention 29.0% vs 13.0%, P < 0.001). Conclusions: Significant differences were observed in the types of indications for ICDs between ACT and IIR. Device prescription differed significantly between countries. The specific reasons for differences in ICD implantation patterns in these two countries are unclear. These observations warrant further investigations to determine if these differences are associated with different qualities of life and clinical outcomes. [source]

    The Dual Chamber and VVI Implantable Defibrillator (DAVID) Trial

    Bruce L. Wilkoff
    Introduction: The devices used to prove the benefit of ICD therapy had only VVI pacing but most current ICD devices provide dual chamber pacing therapy. The DAVID trial sought to measure the impact of dual chamber pacing at 70 bpm (DDDR-70) vs. ventricular backup pacing at 40 bpm (VVI-40) in patients with standard indications for ICD implantation but without indications for bradycardia pacing. Methods: This single-blind, multicenter, parallel-group, randomized clinical trial enrolled 506 patients with indications for ICD therapy between 10/2000 and 9/2002. All patients had an LVEF ,0.40, no indication for pacemaker therapy and no persistent atrial arrhythmias. ICDs with dual chamber, rate-responsive pacing capability were implanted and programmed to VVI-40 or DDDR-70. Results: The combined endpoint of mortality or hospitalization for congestive heart failure (CHF) at one year was 16.1% (VVI-40) vs. 26.7% (DDDR-70), (p , 0.03), mortality 6.5% vs. 10.1% (p , 0.15) and CHF hospitalization 13.3% vs. 22.5% (p , 0.07). Conclusion: For ICD patients, DDDR-70 pacing exhibits no clinical advantage over VVI-40 pacing and may increase CHF and mortality. [source]

    Transvenous Pacemaker Insertion Ipsilateral to Chronic Subclavian Vein Obstruction: An Operative Technique for Children and Adults

    OVADIA, M., et al.: Transvenous Pacemaker Insertion Ipsilateral to Chronic Subclavian Vein Obstruction: An Operative Technique for Children and Adults. Subclavian vein occlusion limits insertion of pacing electrodes in children and adults. The concern is greatest in children with a long-term need for pacing systems necessitating use of the contralateral vein and potential bilateral loss of access in the future. We describe an operative technique to provide ipsilateral access in chronic subclavian vein occlusion in five consecutive pediatric (n = 4, mean age 6.5 years) and adult (n = 1, age 70 with bilateral subclavian vein occlusion) patients in whom this condition was noted at the time of pacemaker or ICD implant. Occlusion was documented by venography. Pediatric cardiac diagnoses included complete heart block in all patients, tetralogy of Fallot in three, and L-transposition of the great vessels in one. Percutaneous brachiocephalic (innominate) or deep subclavian venous access was achieved by a supraclavicular approach using an 18-gauge Deseret angiocath, a Terumo Glidewire, and dilation to permit one or two 9,11 Fr sheaths. Electrode(s) were positioned in the heart and tunneled (pre, or retroclavicularly) to a pre, or retropectoral pocket. Pacemaker and ICD implants were successful in all without any complication of pneumothorax, arterial or nerve injury, or need for transfusion. Inadvertent arterial access did not occur as compared with prior infraclavicular attempts. One preclavicularly tunneled electrode dislodged with extreme exertion and was revised. Ipsilateral transvenous access for pacemaker or ICD is possible via a deep supraclavicular percutaneous approach when the subclavian venous obstruction is discovered at the time of implant. In children, it avoids the use of the contralateral vein that may be needed for future pacing systems in adulthood. This venous approach provides access large enough to allow even dual chamber pacing in children and can be accomplished safely. [source]

    The Importance of Ventricular Septal Morphology in the Effectiveness of Dual Chamber Pacing in Hypertrophic Obstructive Cardiomyopathy

    It has been reported that older patients with hypertrophic obstructive Cardiomyopathy (HOCM) benefited the most from dual chamber (DDD) pacing. Since in older patients the distribution of septal hypertrophy and left ventricular (LV) cavity shape differs from that in younger patients, we decided to study the efficacy of DDD pacing on the reduction of LV outflow tract (LVOT) gradient in different patterns of septal hypertrophy. We compared HOCM patients with nonreversed septal curvature, thus preserving the elliptical LV cavity contour (common in the elderly), (group I) versus patients with reversed septal curvature, deforming the LV cavity to a crescent shape (common in the young), (group II). Eighteen HOCM patients were studied (11 patients in group I and 7 patients in group II). After implantation of a DDD pacemaker, the LVOT gradient was measured using Doppler echocardiography at various programmed AV delay intervals to determine the maximal percentage decrease of LVOT gradient from baseline. The measurement was repeated after at least a 6-month follow-up (chronic DDD pacing). The baseline LVOT gradient was comparable between groups (79 28 vs 81 25 mmHg, P = 0.92). The LVOT gradient reduction at acute DDD pacing was significantly greater in group I than group II (61 18% vs 23 10%, P = 0.0001). This difference in favor of the patients from group I was maintained at midterm follow-up (69 17% vs 40 17% P = 0.0076). In conclusion, patients with normal septal curvature and preserved elliptical LV cavity shape had a greater reduction of LVOT gradient after DDD pacing than patients with reversed septal curvature deforming LV cavity. The proposed criterion assessing the septal curvature may be useful to predict the efficacy of DDD pacing in the reduction of LVOT gradient. [source]

    A Prospective Randomized-Controlled Trial of Ventricular Fibrillation Detection Time in a DDDR Ventricular Defibrillator

    Implantable cardioverter defibrillators (ICDs) with dual chamber and dual chamber rate responsive pacing may offer hemodynamic advantages for some ICD patients. Separate ICDs and DDDR pacemakers can result in device to device interactions, inappropriate shocks, and underdetection of ventricular fibrillation (VF). The objectives of this study were to compare the VF detection times between the Ventak AV II DR and the Ventak AV during high rate DDDR and DDD pacing and to test the safety of dynamic ventricular refractory period shortening. Patients receiving an ICD were randomized in a paired comparison to pacing at 150 beats/min (DDD pacing) or 175 beats/min (DDDR pacing) during ICD threshold testing to create a "worst case scenario" for VF detection. The VF detection rate was set to 180 beats/min, and VF was induced during high rate pacing with alternating current. The device was then allowed to detect and treat VF. The induction was repeated for each patient at each programmed setting so that all patients were tested at both programmed settings. Paired analysis was performed. Patient characteristics were a mean age of 69 11 years, 78% were men, coronary artery disease was present in 85%, and a mean left ventricular ejection fraction of 0.34 0.11. Fifty-two episodes of VF were induced in 26 patients. Despite the high pacing rate, all VF episodes were appropriately detected. The mean VF detection time was 2.4 1.0 seconds during DDD pacing and 2.9 1.9 seconds during DDDR pacing (P = NS). DDD and DDDR programming resulted in appropriate detection of all episodes of VF with similar detection times despite the "worst case scenario" tested. Delays in detection may be seen with long programmed ventricular refractory periods which shorten the VF sensing window and may be avoided with dynamic ventricular refractory period shortening. [source]