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Premature Contractions (premature + contraction)
Selected AbstractsComplete Heart Block Induced and Terminated by a Premature ContractionJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 12 2005SIMON KANGAVARI M.D. No abstract is available for this article. [source] Impact of Preceding Ventricular Premature Beats on Heart Rate TurbulenceANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 4 2009Hung Yi Chen M.D. Background: Heart rate turbulence (HRT) has recently been introduced as a noninvasive tool for studying autonomic dysfunction. It presented short time fluctuation of sinus cycle length following single ventricular premature contraction (VPC). However, HRT parameters may be influenced by different factors. This study aimed to evaluate the possible influence of VPC frequency on HRT. Methods: 24-h Holter recording was performed in patients with VPCs initially detected by 12-lead electrocardiography (ECG) in the outpatient department. The numbers of VPCs in 2- and 5-minute durations preceding each VPC tachogram were calculated. The HRT parameters and the numbers of the VPCs preceding VPC tachograms were analyzed. Results: There were 23,122 available VPC tachograms from 107 healthy subjects included in the study. The turbulence onset (TO) value increased and the turbulence slope (TS) value decreased as VPC's frequency increased. The TO values rapidly increased when the number of VPCs was >15 beats in the 2-minute and >35 beats in the 5-minute durations. There was also a prominent decrease in TS values when the VPCs reached 14 and 30 beats in the 2- and 5-minute durations, respectively. Conclusion: Physiologic baroreflex may be attenuated under intensive stimulation, which is evidenced by blunted HRT parameters by frequent VPCs. Physiologic response to VPC's frequency may be related to baroreflex fatigue and is demonstrated as a sigmoid curve. [source] Perioperative Ventricular Arrhythmias in Patients Undergoing Partial Left VentriculectomyJOURNAL OF CARDIAC SURGERY, Issue 2 2001Toshimi Ujiie M.D. Background: Although incidence of ventricular arrhythmias after partial left ventriculectomy (PLV) has been reported, there are no studies comparing incidence before and after PLV. Although operative scars may give rise to arrhythmias, improved energetic efficiency after PLV may decrease their incidence. Methods: Pre- and postoperative ventricular arrhythmias were monitored by Holter ECG and analyzed in 17 patients undergoing PLV in Curitiba, Brazil. Results: Although total 24-hour heart beat (THB) increased significantly (p = 0.018), ventricular premature contractions (VPCs) decreased markedly (p = 0.036), excluding one patient dying in low cardiac output (LOS) who had terminal arrhythmias increased multifold. In the remaining 16 patients, VPC pairs were also reduced significantly on the average (p = 0.038). In contrast, ventricular tachycardia (VT; more than three consecutive VPCs) disappeared in five patients, decreased in two patients, and newly occurred in four patients, with five patients showing no change; one of them developed a prolonged VT, successfully reversed by external cardioversion. Conclusions: Despite notable significant increase in THB immediately after PLV, PVC and PVC pairs were significantly decreased in contrast to VT, which disappeared in some patients and newly occurred in other patients, remaining constant on the average. Sustained VT occurring in a patient with all other arrhythmias suppressed may suggest a unique electrophysiological substrate, may justify prophylactic use of amiodarone or an implantable cardioverter-defibrillator, and may underscore the importance of further and extended studies. [source] Cardiac monitoring of patients receiving arsenic trioxide therapyBRITISH JOURNAL OF HAEMATOLOGY, Issue 5 2004Dilip Unnikrishnan Summary Arsenic trioxide (ATO) is approved for the treatment of acute promyelocytic leukaemia and is under investigation for other malignancies. We report the cardiac findings in 18 patients with haematologic malignancies treated with ATO and assess the role of cardiac factors in fluid retention syndrome observed during ATO therapy. Based on initial observations in 10 patients treated with ATO, cardiac functions in the subsequent eight patients were evaluated prospectively. Evaluation included pre- and during-treatment electrocardiograms, Holter monitoring, echocardiograms, multigated acquisition scan and cardiac stress tests if indicated. All eight patients developed fluid retention during ATO, evidenced by pulmonary congestion, oedema and pleural/pericardial effusions. No cardiac factors were identified that contributed to fluid retention. Six patients had prolonged corrected QT (QTc) compared with baseline, three developed ventricular tachycardia. Sinus tachycardia, ventricular premature contractions, and non-sustained ventricular/supraventricular tachycardia were seen during ATO treatment. Fluid retention and cardiac events did not correlate with the dose or total amount of ATO or prior anthracycline therapy. In summary, fluid overload during ATO therapy does not appear to be cardiac in origin but appears to be drug-related, and may reflect cytokine-induced capillary leak. QTc prolongation, transient arrhythmias and clinically significant arrhythmias were seen with therapeutic doses of ATO. [source] | ||||||||||