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Ventricular Response (ventricular + response)

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Medical Sciences100%

Selected Abstracts

Combined Longitudinal and Radial Dyssynchrony Predicts Ventricular Response After Resynchronization Therapy

CONGESTIVE HEART FAILURE, Issue 2 2008
Article first published online: 2 MAY 200
No abstract is available for this article. [source]

Radiofrequency Energy Modification of the Atrioventricular Junction in Patients with Atrial Fibrillation: Modes of Ventricular Response Under Autonomic Blockade and Long-Term Effect

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2001
HARALAMPOS D. KRIATSELIS
KRIATSELIS, H.D., et al.: Radiofrequency Energy Modification of the Atrioventricular Junction in Patients with Atrial Fibrillation: Modes of Ventricular Response Under Autonomic Blockade and Long-Term Effect. The short- and long-term effect of radiofrequency (RF) modification of the AV junction on ventricular rate and left ventricular function and the different types of ventricular response during energy application under autonomic nervous blockade were assessed in 28 patients with medically refractory atrial fibrillation. During the successful RF application, ventricular rate slowed progressively (type I response, ten patients) or accelerated at first and then slowed (type II response, 11 patients). Type II response was associated with a more anterior ablation site compared to Type I response. A primary successful outcome was achieved in 21 patients. Inadvertent complete AV block developed in three patients, while in four patients AV nodal ablation was performed after an unsuccessful modification attempt. During 6-month follow-up, the ventricular rate was adequately controlled in only four patients. Among the 16 patients with a recurrence of uncontrolled AF were all 10 patients with type I response and 6 of 11 patients with type II response. One patient died suddenly 10 weeks after the procedure. [source]

Orthodromic Pacemaker-Mediated Tachycardia in a Biventricular System Without an Atrial Electrode

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 9 2004
ANTONIO BERRUEZO M.D.
Pacemaker-mediated tachycardia is a well-known complication of dual-chamber devices. In this report, we describe for the first time a case of orthodromic pacemaker-mediated tachycardia in a patient in whom a biventricular system without an atrial electrode had been implanted. Retrograde atrial activation was directly produced by the dislodged coronary vein electrode in the AV groove, resulting in simultaneous capture of the left atrium and left ventricle. During tachycardia, AV nodal conduction was via the anterograde pathway of the circuit and limited the ventricular response. Subsequently, right ventricular activation was sensed by the right ventricular electrode that triggered biventricular pacing and left atrial capture, perpetuating the tachycardia. Because the left atrial threshold was higher than the left ventricular threshold, the problem could be resolved easily by lowering the output of the coronary vein electrode. [source]

Incessant Nonreentrant Tachycardia Due to Simultaneous Conduction Over Dual Atrioventricular Nodal Pathways Mimicking Atrial Fibrillation in Patients Referred for Pulmonary Vein Isolation

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 7 2003
Moussa Mansour M.D.
It has been reported that conduction over the fast and slow pathways of the AV node can occur simultaneously, leading to a double ventricular response from each atrial beat. We report the cases of two patients referred to us for evaluation of symptomatic, incessant, and irregular narrow-complex tachycardia, misdiagnosed as atrial fibrillation, for consideration of pulmonary vein isolation. At presentation, careful evaluation of the electrograms revealed the presence of two ventricular activations for each atrial beat. At electrophysiologic study, both patients were found to have nonreentrant tachycardias arising from simultaneous conduction over the fast and slow pathways of the AV node. In one patient, the tachycardia had resulted in cardiomyopathy. Slow AV nodal pathway ablation performed in both patients resulted in cure of their tachycardias and recovery of ventricular function in the patient with cardiomyopathy. (J Cardiovasc Electrophysiol, Vol. 14, pp. 752-755, July 2003) [source]

Bimodal RR Interval Distribution in Chronic Atrial Fibrillation:

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 5 2000
Impact of Dual Atrioventricular Nodal Physiology on Long-Term Rate Control after Catheter Ablation of the Posterior Atrionodal Input
Bimodal RR Interval Distribution, Introduction: Radiofrequency (RF) catheter modification of the AV node hi patients with atrial fibrillation (AF) is limited by an unpredictable decrease of the ventricular rate and a wish incidence of permanent AV block, A bimodal RR histogram has been suggested to serve as a predictor for successful outcome but the corresponding AV node properties have never been characterized, We hypothesized that a bimodal histogram indicates dual AV nodal physiology and predicts a better outcome after AV node modification in chronic AF. Methods and Results: Thirty-seven patients were prospectively subdivided into two groups according to the RR histogram of 24-hour ECC monitoring, Before to RF ablation, internal cardioversion and programmed stimulation were performed, Among the 22 patients (group I) with a bimodal RR histogram, dual AV nodal physiology was found in 17 (779f) patients, Ablation significantly decreased ventricular rate with loss of the peak of short RR cycles after ablation (mean and maximal ventricular rates: 32% and 35% rate reduction, respectively; P < 0,01), In 15 patients with a unimodal RR histogram (group II), dual AV nodal physiology was found in 2 (13%), and rate reductions were 16% and 17%, respectively, At 6 months, 3 (14%) patients in group 1 and 6 (40%) in group II underwent elective AV nodal ablation with pacemaker implantation due to intolerable rapid ventricular response to AF. Conclusion: Bimodal RR interval distribution during chronic AF suggests the presence of dual AV nodal physiology and predicts a better outcome of RF ablation of the posterior atrionocdal input. [source]

Radiofrequency Energy Modification of the Atrioventricular Junction in Patients with Atrial Fibrillation: Modes of Ventricular Response Under Autonomic Blockade and Long-Term Effect

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2001
HARALAMPOS D. KRIATSELIS
KRIATSELIS, H.D., et al.: Radiofrequency Energy Modification of the Atrioventricular Junction in Patients with Atrial Fibrillation: Modes of Ventricular Response Under Autonomic Blockade and Long-Term Effect. The short- and long-term effect of radiofrequency (RF) modification of the AV junction on ventricular rate and left ventricular function and the different types of ventricular response during energy application under autonomic nervous blockade were assessed in 28 patients with medically refractory atrial fibrillation. During the successful RF application, ventricular rate slowed progressively (type I response, ten patients) or accelerated at first and then slowed (type II response, 11 patients). Type II response was associated with a more anterior ablation site compared to Type I response. A primary successful outcome was achieved in 21 patients. Inadvertent complete AV block developed in three patients, while in four patients AV nodal ablation was performed after an unsuccessful modification attempt. During 6-month follow-up, the ventricular rate was adequately controlled in only four patients. Among the 16 patients with a recurrence of uncontrolled AF were all 10 patients with type I response and 6 of 11 patients with type II response. One patient died suddenly 10 weeks after the procedure. [source]

The GH,IGF-I axis and the cardiovascular system: clinical implications

CLINICAL ENDOCRINOLOGY, Issue 3 2008
Annamaria Colao
Summary Background, GH and IGF-I affect cardiac structure and performance. In the general population, low IGF-I has been associated with higher prevalence of ischaemic heart disease and mortality. Both in GH deficiency (GHD) and excess life expectancy has been reported to be reduced because of cardiovascular disease. Objective, To review the role of the GH,IGF-I system on the cardiovascular system. Results, Recent epidemiological evidence suggests that serum IGF-I levels in the low-normal range are associated with increased risk of acute myocardial infarction, ischaemic heart disease, coronary and carotid artery atherosclerosis and stroke. This confirms previous findings in patients with acromegaly or with GH-deficiency showing cardiovascular impairment. Patients with either childhood- or adulthood-onset GHD have cardiovascular abnormalities such as reduced cardiac mass, diastolic filling and left ventricular response at peak exercise, increased intima-media thickness and endothelial dysfunction. These abnormalities can be reversed, at least partially, after GH replacement therapy. In contrast, in acromegaly chronic GH and IGF-I excess causes a specific cardiomyopathy: concentric cardiac hypertrophy (in more than two-thirds of the patients at diagnosis) associated to diastolic dysfunction is the most common finding. In later stages, impaired systolic function ending in heart failure can occur, if GH/IGF-I excess is not controlled. Abnormalities of cardiac rhythm and of cardiac valves can also occur. Successful control of acromegaly is accompanied by decrease of the left ventricular mass and improvement of cardiac function. Conclusion, The cardiovascular system is a target organ for GH and IGF-I. Subtle dysfunction in the GH,IGF-I axis are correlated with increased prevalence of ischaemic heart disease. Acromegaly and GHD are associated with several abnormalities of the cardiovascular system and control of GH/IGF-I secretion reverses (or at least stops) cardiovascular abnormalities. [source]