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Biomedical subjects

Pierre Bordachar

Publications and source records attributed to Pierre Bordachar.

18 recordsLinked to original sources
PubMed2006

Outcome after implantation of a cardioverter-defibrillator in patients with Brugada syndrome: a multicenter study.

BACKGROUND: Brugada syndrome is an arrhythmogenic disease characterized by an increased risk of sudden cardiac death (SCD) by ventricular fibrillation. At present, an implantable cardioverter-defibrillator (ICD) is the recommended therapy in high-risk patients. This multicenter study reports the outcome of a large series of patients implanted with an ICD for Brugada syndrome. METHODS AND RESULTS: All patients (n=220, 46+/-12 years, 183 male) with a type 1 Brugada ECG pattern implanted with an ICD in 14 centers between 1993 and 2005 were investigated. ICD indication was based on resuscitated SCD (18 patients, 8%), syncope (88 patients, 40%), or positive electrophysiological study in asymptomatic patients (99 patients, 45%). The remaining 15 patients received an ICD because of a family history of SCD or nonsustained ventricular arrhythmia. During a mean follow-up of 38+/-27 months, no patient died and 18 patients (8%) had appropriate device therapy (10+/-15 shocks/patient, 26+/-33 months after implantation). The complication rate was 28%, including inappropriate shocks, which occurred in 45 patients (20%, 4+/-3 shocks/patient, 21+/-20 months after implantation). The reasons for inappropriate therapy were lead failure (19 patients), T-wave oversensing (10 patients), sinus tachycardia (10 patients), and supraventricular tachycardia (9 patients). Among implantation parameters, high defibrillation threshold, high pacing threshold, and low R-wave amplitude occurred, respectively, in 12%, 27%, and 15% of cases. CONCLUSIONS: In this large Brugada syndrome population, a low incidence of arrhythmic events was found, with an annual event rate of 2.6% during a follow-up of >3 years, in addition to a significant risk of device-related complications (8.9%/year). Inappropriate shocks were 2.5 times more frequent than appropriate ones.

Adult↗
PubMed2006

Effects of right, left, and biventricular pacing on myocardial perfusion in ischemic conditions.

OBJECTIVES: In normal hearts, the distribution of regional myocardial perfusion is altered by ventricular pacing. Little is known about the impact of ventricular pacing on regional myocardial perfusion in ischemic conditions. In this acute echocardiographic study, we compared the respective effects of right ventricular pacing (RVP), left ventricular pacing (LVP), and biventricular pacing (BVP) on regional perfusion in a swine model of graded ischemia. METHODS AND RESULTS: Ventricular pacing leads were placed at the apex of the right ventricle and on the lateral wall of the left ventricle in nine open-chest pigs. Myocardial contrast echocardiography was successively performed during spontaneous rhythm (SR), RVP, LVP, and BVP in random order at baseline and during three stages of incremental ischemia (left anterior descending + circumflex). At baseline, RVP decreased myocardial perfusion of the septal and inferior walls compared to SR (P < 0.05), whereas LVP decreased perfusion of the lateral wall (P < 0.05). No significant differences were observed in regional perfusion during BVP compared to SR. In ischemic conditions, RVP worsened myocardial perfusion in the ischemic anterior wall as well as in the septal and inferior walls (P < 0.05), whereas both LVP and BVP did not alter perfusion in the ischemic area compared to SR. CONCLUSION: Compared to baseline, in ischemic conditions, RVP has a more pronounced detrimental impact on perfusion abnormalities. In contrast, BVP induced a significant improvement in local myocardial perfusion. Therefore, BVP could be preferred to RVP in patients with ischemic cardiomyopathy.

Animals↗
PubMed2006

Dynamic ventricular dyssynchrony: an exercise-echocardiography study.

OBJECTIVES: We sought to assess the effects of exercise on ventricular dyssynchrony in patients with normal and depressed left ventricular (LV) function. BACKGROUND: Asynchronous myocardial contraction adversely influences ventricular function and is associated with a poor prognosis in heart failure. Exercise-induced changes in ventricular dyssynchrony may be an important determinant of dynamic changes in cardiac output and mitral regurgitation. METHODS: A total of 65 consecutive heart failure patients and 50 matched healthy control patients underwent exercise echocardiography. Conventional and tissue Doppler parameters were measured before and during symptom-limited exercise. Left ventricular dyssynchrony was defined as the standard deviation of 12 LV segmental electromechanical delays. Analysis of the control group allowed delimitation of normal cutoff values. RESULTS: In patients with normal left ventricular function, exercise did not modify the extent of LV asynchrony. In contrast, in heart failure patients, LV dyssynchrony increased by at least 20% in 34%, remained stable in 37%, and decreased by at least 20% in 29%. Moreover, 26% of heart failure patients had either exercise induction or normalization of ventricular dyssynchrony. A significant association was found between exercise-induced changes in dyssynchrony and the presence of ischemic cardiomyopathy (p < 0.05). Rest-exercise differences in ventricular dyssynchrony were correlated with changes in cardiac output and mitral regurgitation (r = -0.63 and 0.56, respectively). CONCLUSIONS: In heart failure patients, exercise can alter the magnitude of ventricular dyssynchrony. Some patients have a response to exertion with induction of ventricular dyssynchrony, whereas others show normalization. Changes in ventricular dyssynchrony during exercise correlate with alterations in cardiac output and mitral regurgitation.

Aged↗
PubMed2006

Echocardiographic assessment during exercise of heart failure patients with cardiac resynchronization therapy.

This prospective echocardiographic study investigated the respective impacts of left ventricular (LV) pacing and simultaneous and sequential biventricular pacing (BVP) on ventricular dyssynchrony during exercise in 23 patients with compensated heart failure and ventricular conduction delays. During exercise, LV pacing and BVP significantly (p <0.05) improved mitral regurgitation and LV dyssynchrony compared with spontaneous activation. LV segmental electromechanical delays were significantly prolonged during LV pacing, leading to increased systolic time (p <0.05), decreased LV filling time (p <0.05), and decreased stroke volume (p <0.05) compared with BVP. After optimization of the interventricular delay with sequential BVP, additional benefit was obtained during exercise in terms of stroke volume and mitral regurgitation (p <0.05). The optimal interventricular delay was different at rest and during exercise in 57% of the patients. Changes from at rest to exercise in LV dyssynchrony were correlated with changes in stroke volume (r = -0.61, p <0.01) and changes in mitral regurgitation (r = 0.60, p <0.01).

Cardiac Pacing, Artificial↗
PubMed2006

Localized sources maintaining atrial fibrillation organized by prior ablation.

BACKGROUND: Endocardial mapping of localized sources driving atrial fibrillation (AF) in humans has not been reported. METHODS AND RESULTS: Fifty patients with AF organized by prior pulmonary vein and linear ablation were studied. AF was considered organized if mapping during AF showed irregular but discrete atrial complexes exhibiting consistent activation sequences for >75% of the time using a 20-pole catheter with 5 radiating spines covering 3.5-cm diameter or sequential conventional mapping. A site or region centrifugally activating the remaining atrial tissue defined a source. During AF with a cycle length of 211+/-32 ms, activation mapping identified 1 to 3 sources at the origin of atrial wavefronts in 38 patients (76%) predominantly in the left atrium, including the coronary sinus region. Electrograms at the earliest area varied from discrete centrifugal activation to an activity spanning 75% to 100% of the cycle length in 42% of cases, the latter indicating complex local conduction or a reentrant circuit. A gradient of cycle length (>20 ms) to the surrounding atrium was observed in 28%. Local radiofrequency ablation prolonged AF cycle length by 28+/-22 ms and either terminated AF or changed activation sequence to another organized rhythm. In 4 patients, the driving source was isolated, surrounded by the atrium in sinus rhythm, and still firing at high frequency (228+/-31 ms) either permanently or in bursts. CONCLUSIONS: AF associated with consistent atrial activation sequences after prior ablation emanates mostly from localized sources that can be mapped and ablated. Some sources harbor electrograms suggesting the presence of localized reentry.

Aged↗
PubMed2006

Flutter localized to the anterior left atrium after catheter ablation of atrial fibrillation.

INTRODUCTION: Organized atrial arrhythmias following atrial fibrillation (AF) ablation are typically due to recovered pulmonary vein (PV) conduction or reentry at incomplete ablation lines. We describe the role of nonablated anterior left atrium (LA) in arrhythmias observed after AF ablation. METHODS: A total of 275 consecutive patients with paroxysmal (n = 200) or chronic (n = 75) AF had PV isolation with/without additional linear ablation at the mitral isthmus (n = 106), LA roof (n = 23), or both (n = 88). Organized arrhythmias occurring after ablation were evaluated utilizing activation and entrainment mapping. RESULTS: Fourteen patients (11 female, 65 +/- 13 years, 10 chronic AF, 10 structural heart disease) demonstrated tachycardia localized to the anterior LA, an area not targeted by prior ablation. Eight had ECG features during sinus rhythm suggestive of impaired anterior LA conduction at baseline. These arrhythmias demonstrated a distinctive ECG flutter morphology in 7 of 10 (70%) with discrete -/+ or +/-/+ aspect in inferior leads. Mapping the anterior LA revealed electrograms spanning the entire tachycardia cycle length (325 +/- 125 msec). Entrainment was possible in all with a postpacing interval exceeding the tachycardia cycle length by 9 +/- 10 msec. Electroanatomic mapping in 6 demonstrated small reentrant circuits rotating clockwise in 4 and counterclockwise in 2. Low-amplitude, fractionated mid-diastolic potentials with long duration (200 +/- 80 msec) occupying 63 +/- 22% of the cycle length were targeted for ablation resulting in termination and subsequent noninducibility. CONCLUSION: Organized arrhythmias occurring after AF ablation can be due to reentrant circuits localized to the anterior LA, predominantly in females with chronic AF, structural heart disease, and abnormal atrial conduction. They are characterized by a distinctive surface ECG and highly responsive to RF ablation at the slow conduction area.

Aged↗
PubMed2005

Catheter ablation of long-lasting persistent atrial fibrillation: critical structures for termination.

BACKGROUND: The relative contributions of different atrial regions to the maintenance of persistent atrial fibrillation (AF) are not known. METHODS: Sixty patients (53 +/- 9 years) undergoing catheter ablation of persistent AF (17 +/- 27 months) were studied. Ablation was performed in a randomized sequence at different left atrial (LA) regions and comprised isolation of the pulmonary veins (PV), isolation of other thoracic veins, and atrial tissue ablation targeting all regions with rapid or heterogeneous activation or guided by activation mapping. Finally, linear ablation at the roof and mitral isthmus was performed if sinus rhythm was not restored after addressing the above-mentioned areas. The impact of ablation was evaluated by the effect on the fibrillatory cycle length in the coronary sinus and appendages at each step. Activation mapping and entrainment maneuvers were used to define the mechanisms and locations of intermediate focal or macroreentrant atrial tachycardias. RESULTS: AF terminated in 52 patients (87%), directly to sinus rhythm in 7 or via the ablation of 1-6 intermediate atrial tachycardias (total 87) in 45 patients. This conversion was preceded by prolongation of fibrillatory cycle length by 39 +/- 9 msec, with the greatest magnitude occurring during ablation at the anterior LA, coronary sinus and PV-LA junction. Thirty-eight atrial tachycardias were focal (originating dominantly from these same sites), while 49 were macroreentrant (involving the mitral or cavotricuspid isthmus or LA roof). Patients without AF termination displayed shorter fibrillatory cycles at baseline: 130 +/- 14 vs 156 +/- 23 msec; P = 0.002. CONCLUSION: Termination of persistent AF can be achieved in 87% of patients by catheter ablation. Ablation of the structures annexed to the left atrium-the left atrial appendage, coronary sinus, and PVs-have the greatest impact on the prolongation of AF cycle length, the conversion of AF to atrial tachycardia, and the termination of focal atrial tachycardias.

Atrial Fibrillation↗
PubMed2005

Catheter ablation of long-lasting persistent atrial fibrillation: clinical outcome and mechanisms of subsequent arrhythmias.

BACKGROUND: Catheter ablation of atrial fibrillation (AF) is challenging in patients with long-standing persistent AF. The clinical outcome and subsequent arrhythmia recurrence after using an ablation method targeting multiple left atrial sites with the aim of achieving acute AF termination has not been characterized. METHODS: Sixty patients (mean age: 53 +/- 9 years) with persistent AF (mean duration: 17 +/- 27 months) were prospectively followed after catheter ablation. Catheter ablation targeting the following sites was performed in a random sequence: (i) electrical isolation of all pulmonary veins (PV); (ii) disconnection of other thoracic veins; (iii) atrial ablation at sites possessing complex electrical activity, activation gradients, or short cycle lengths. Finally, linear ablation of the LA roof and mitral isthmus was performed if sinus rhythm was not restored following energy delivery to the above sites. At 1, 3, 6, and 12 months after ablation, patients underwent clinical review and 24-hour ambulatory ECG monitoring to identify asymptomatic arrhythmia. Repeat mapping and catheter ablation was performed in any patient experiencing recurrent atrial tachycardia (AT). Clinical success was defined as the absence of any sustained atrial arrhythmia. RESULTS: AF terminated during ablation in 52 patients (87%). The fluoroscopy and procedural durations were 84 +/- 30 minutes and 264 +/- 77 minutes, respectively. Three months after ablation, sustained ATs were documented in 24 patients (associated with AF in 2). Mapping in 23 patients showed a single AT in 7 while multiple ATs were observed in 16. Macroreentry was confirmed to be due to gaps in the ablation lines, while focal ATs originated from discrete sites or isthmuses near the left atrial appendage, coronary sinus, pulmonary veins, or fossa ovalis; these sites were similar to those at which the greatest impact was observed on the fibrillatory process during the initial ablation procedure. After repeat ablation, at 11 +/- 6 months of follow-up, 57 patients (95%) were in sinus rhythm and 3 developed recurrent AF or AT. All patients in sinus rhythm demonstrated improved exercise capacity and all but 2 had evidence of atrial transport as assessed by Doppler echocardiography (mitral A wave velocity 34 +/- 17 cm/sec) by 6 months. CONCLUSION: Catheter ablation of long-lasting persistent AF associated with acute AF termination achieves medium to long-term restoration and maintenance of sinus rhythm in 95% of patients. Arrhythmia recurrence in the majority of patients is AT.

Adult↗
PubMed2004

Echocardiographic parameters of ventricular dyssynchrony validation in patients with heart failure using sequential biventricular pacing.

OBJECTIVES: We sought to evaluate the relationship between hemodynamic and ventricular dyssynchrony parameters in patients undergoing simultaneous and sequential biventricular pacing (BVP). BACKGROUND: Various echocardiographic parameters of ventricular dyssynchrony have been proposed to screen and optimize BVP therapy. METHODS: Forty-one patients with heart failure undergoing BVP implantation were studied. Echocardiography coupled with tissue tracking and pulsed Doppler tissue imaging (DTI) was performed before and after BVP implantation and after three months of optimized BVP. Indexes of inter- or intraventricular dyssynchrony were correlated with hemodynamic changes during simultaneous and sequential BVP (10 intervals of right ventricular [RV] or left ventricular [LV] pre-excitation). RESULTS: Variations in intra-LV delay(peak), intra-LV delay(onset), and index of LV dyssynchrony measured by pulsed DTI were highly correlated with those of cardiac output (r = -0.67, r = -0.64, and r = -0.67, respectively; p < 0.001) and mitral regurgitation (r = 0.68, r = 0.63, and r = 0.68, respectively; p < 0.001), whereas variations in the extent of myocardium displaying delayed longitudinal contraction (r = -0.48 and r = 0.51, respectively; p < 0.05) and the variations in septal-to-posterior wall motion delay (r = -0.41, p < 0.05 and r = 0.24, p = NS, respectively) were less correlated. The changes in interventricular dyssynchrony were not significantly correlated (p = NS). Compared with simultaneous BVP, individually optimized sequential BVP significantly increased cardiac output (p < 0.01), decreased mitral regurgitation (p < 0.05), and improved all parameters of intra-LV dyssynchrony (p < 0.01). At three months, a significant reverse mechanical LV remodeling was observed with significantly decreased LV volumes (p < 0.01) associated with an increased LV ejection fraction (p = 0.035). CONCLUSIONS: Specific echocardiographic measurements of ventricular dyssynchrony are highly correlated with hemodynamic changes and may be a useful adjunct in the selection and optimization of BVP. Individually optimized sequential BVP provided a significant early hemodynamic improvement compared with simultaneous BVP.

Aged↗
PubMed2004

Detrimental ventricular remodeling in patients with congenital complete heart block and chronic right ventricular apical pacing.

BACKGROUND: Although dual-chamber pacing improves cardiac function in patients with complete congenital atrioventricular block (CCAVB) by restoring physiological heart rate and atrioventricular synchronization, the long-term detrimental effect of asynchronous electromechanical activation induced by apical right ventricular pacing (RVP) has not been well clarified. METHODS AND RESULTS: Twenty-three CCAVB adults (24+/-3 years) with a DDD transvenous pacemaker underwent conventional echocardiography before implantation and, after at least 5 years of RVP, an exercise test and echocardiography coupled with tissue Doppler imaging and tissue tracking. They were compared with 30 matched healthy control subjects. After 10+/-3 years of RVP, CCAVB adults had significantly higher values versus controls in terms of intra-left ventricular (LV) asynchrony (respectively, 59+/-18 versus 19+/-9 ms, P<0.001), extent of LV myocardium displaying delayed longitudinal contraction (39+/-15% versus 10+/-7%, P<0.01), and septal-to-posterior wall-motion delay (84+/-26 versus 18+/-9 ms, P<0.01). The ratio of late-activated posterior to early-activated septal wall thickness was higher after long-term RVP than before (1.3+/-0.2 vs 1+/-0.1, P=0.05) and was higher than in controls (1+/-0.1, P<0.05). The percentage of patients with increased LV end-diastolic diameter was higher after long-term RVP than before implantation and was higher than in controls (57% versus 13%, P<0.05, and 57% versus 0%, P<0.01, respectively). CCAVB patients with long-term RVP had a lower cardiac output than controls (3.8+/-0.6 versus 4.9+/-0.8 L/min, P<0.05) and lower exercise performance (123+/-24 versus 185+/-39 W, P<0.001). CONCLUSIONS: Prolonged ventricular dyssynchrony induced by long-term endovenous RVP is associated with deleterious LV remodeling, LV dilatation, LV asymmetrical hypertrophy, and low exercise capacity. These new data highlight the importance of the ventricular activation sequence in all patients with chronic ventricular pacing.

Adult↗
PubMed2004

Catheter ablation for atrial fibrillation in congestive heart failure.

BACKGROUND: Congestive heart failure and atrial fibrillation often coexist, and each adversely affects the other with respect to management and prognosis. We prospectively evaluated the effect of catheter ablation for atrial fibrillation on left ventricular function in patients with heart failure. METHODS: We studied 58 consecutive patients with congestive heart failure and a left ventricular ejection fraction of less than 45 percent who were undergoing catheter ablation for atrial fibrillation. We selected as controls 58 patients without congestive heart failure who were undergoing ablation for atrial fibrillation, matched according to age, sex, and classification of atrial fibrillation. We evaluated the patients' left ventricular function and dimensions, symptom score, exercise capacity, and quality of life at baseline and at months 1, 3, 6, and 12. RESULTS: After a mean (+/-SD) of 12+/-7 months, 78 percent of the patients with congestive heart failure and 84 percent of the controls remained in sinus rhythm (P=0.34) (69 percent and 71 percent, respectively, were in sinus rhythm without the administration of antiarrhythmic drugs). The patients with congestive heart failure had significant improvement in left ventricular function (increases in the ejection fraction and fractional shortening of 21+/-13 percent and 11+/-7 percent, respectively; P<0.001 for both comparisons), left ventricular dimensions (decreases in the diastolic and systolic diameters of 6+/-6 mm and 8+/-7 mm, respectively; P=0.03 and P<0.001, respectively), exercise capacity, symptoms, and quality of life. The ejection fraction improved significantly not only in patients without concurrent structural heart disease (24+/-10 percent, P<0.001) and those with inadequate rate control before ablation (23+/-10 percent, P<0.001), but also in those with coexisting heart disease (16+/-14 percent, P<0.001) and adequate rate control before ablation (17+/-15 percent, P<0.001). CONCLUSIONS: Restoration and maintenance of sinus rhythm by catheter ablation without the use of drugs in patients with congestive heart failure and atrial fibrillation significantly improve cardiac function, symptoms, exercise capacity, and quality of life.

Aged↗
PubMed2004

Improvement of left ventricular wall synchronization with multisite ventricular pacing in heart failure: a prospective study using Doppler tissue imaging.

UNLABELLED: We sought to assess right, left and biventricular pacing effects on myocardial function by using pulsed-Doppler tissue imaging (DTI) and automated border detection (ABD) techniques which provide electromechanical delay (EMD) assessment of the different left ventricular walls. METHODS: 15 patients (67+/-7 years) with drug-resistant primitive dilated cardiomyopathy and QRS> or =140 ms received a pacemaker for multisite ventricular pacing. Echocardiography was performed after 1 month of biventricular pacing (BVP). Echocardiographic measurements were recorded during spontaneous rhythm (SpR), right ventricular pacing (RVP), left ventricular pacing (LVP) and BVP. RESULTS: LV ejection fraction was statistically similar between the four rhythms. BVP showed a significant EMD decrease for the lateral LV wall vs. SpR, RVP and even LVP. LVP resulted in significantly longer aortic pre-ejection time vs. BVP while the EMD temporal dispersion (time between the shortest regional EMD and the longest one) was similar in the two modes. CONCLUSIONS: BVP and LVP substantially reduce the EMD temporal dispersion of the four LV walls, but with a longer aortic pre-ejection time for LVP. In RVP, LVP and BVP, the septal LV wall is always activated later than during SpR. BVP and LVP are associated with a mitral regurgitation reduction.

Aged↗
PubMed2004

Incidence, clinical implications and prognosis of atrial arrhythmias in Brugada syndrome.

AIMS: This single-centre prospective study was designed to determine the incidence, therapeutic implications and prognosis of atrial arrhythmias (AA) in patients with Brugada syndrome (BS). METHODS AND RESULTS: Fifty nine consecutive patients with BS and 31 age and gender-matched controls underwent an electrophysiological exploration and were followed-up during 34+/-13 months. The final AA incidence was 20% in BS patients vs 0% in controls (p < 0.01). Ventricular inducibility was significantly related to a history of AA (p = 0.02). The incidence of AA in patients with a spontaneous electrocardiogram of BS was 26% vs 10% in patients with a flecainide-induced electrocardiogram (p < 0.05). In patients with an indication of implantable cardioverter defibrillator (ICD), the incidence of AA reached 27% vs 13% in patients with BS but without ICD indication (p < 0.05). Inappropriate shocks due to AA episodes were observed in 14% of ICD patients vs 10.5% of appropriate shocks. Multivariate analysis identified the implantation of a single-chamber device as an independent predictive factor of inappropriate ICD discharges (p < 0.05). CONCLUSION: BS patients exhibit an abnormally high proportion of AA. Our data strongly suggest a more advanced disease process in BS patients with spontaneous AA. Careful programming of single-chamber ICD should be recommended to avoid inappropriate discharges.

Adult↗
PubMed2004

Chronic cor pulmonale: a rare complication of undiagnosed pacemaker lead endocarditis.

Pacemaker lead infection is a rare life-threatening complication of permanent transvenous pacing. We describe the case of a young man who suffered recurrent undiagnosed septic pulmonary embolisms from pacemaker lead vegetations inducing chronic cor pulmonale with major pulmonary arterial hypertension. The potential complications of transvenous pacing and the systematic use of transesophageal echocardiography are emphasized.

Adult↗
PubMed2004

Biventricular pacing and left ventricular pacing in heart failure: similar hemodynamic improvement despite marked electromechanical differences.

INTRODUCTION: We conducted an acute echocardiographic study comparing hemodynamic and ventricular dyssynchrony parameters during left ventricular pacing (LVP) and biventricular pacing (BVP). We sought to clarify the mechanisms responsible for similar hemodynamic improvement despite differences in electrical activation. METHODS AND RESULTS: Thirty-three patients underwent echocardiography prior to implantation with a multisite pacing device (spontaneous rhythm [SR]) and 2 days after implantation (BVP and LVP). Interventricular dyssynchrony (pulsed-wave Doppler), extent of myocardium displaying delayed longitudinal contraction (%DLC; tissue tracking), and index of LV dyssynchrony (pulsed-wave tissue Doppler imaging) were assessed. Compared to SR, BVP and LVP caused similar significant improvement of cardiac output (LVP: 3.2 +/- 0.5, BVP: 3.1 +/- 0.7, SR: 2.3 +/- 0.6 L/min; P < 0.01) and mitral regurgitation (LVP: 25.1 +/- 10, BVP: 24.7 +/- 11, baseline: 37.9 +/- 14% jet area/left atria area; P < 0.01). LVP resulted in a smaller index of LV dyssynchrony than BVP (29 +/- 10 vs 34 +/- 14; P < 0.05). However, LVP exhibited a longer aortic preejection delay (220 +/- 34 vs 186 +/- 28 msec; P < 0.01), longer LV electromechanical delays (244.5 +/- 39 vs 209.5 +/- 47 msec; P < 0.05), greater interventricular dyssynchrony (56.6 +/- 18 vs 31.4 +/- 18; P < 0.01), and higher%DLC (40.1 +/- 08 vs 30.3 +/- 09; P < 0.05), leading to shorter LV filling time (387 +/- 54 vs 348 +/- 44 msec; P < 0.05) compared to BVP. CONCLUSION: Although LVP and BVP provide similar hemodynamic improvement, LVP results in more homogeneous but substantially delayed LV contraction, leading to shortened filling time and less reduction in postsystolic contraction. These data may influence the choice of individual optimal pacing configuration.

Aged↗
PubMed2004

Death during polysomnography of a patient with cheyne-stokes respiration, respiratory acidosis, and chronic heart failure.

A patient with chronic heart failure and chronic respiratory failure (CRF) underwent ambulatory polysomnography at home. She was found dead on the morning after the recording. The tracings confirmed severe sleep apnea syndrome. After 8 h of incessant Cheyne-Stokes respiration during sleep, respiratory arrest occurred, followed 7 min later by asystole. This report illustrates a case of respiratory drive failure during sleep as the mode of death in a patient with heart failure, sleep apnea syndrome, and CRF.

Acidosis, Respiratory↗
PubMed2003

Comparison of permanent left ventricular and biventricular pacing in patients with heart failure and chronic atrial fibrillation: a prospective hemodynamic study.

BACKGROUND: Left ventricular pacing (LVP) and biventricular pacing (BVP) have been proposed as treatments for patients with advanced heart failure complicated by discoordinate contraction due to intraventricular conduction delay. For patients in sinus rhythm, BVP works in part by modulating the electronic atrial-ventricular time delay and thus optimizing contractile synchrony, the contribution of atrial systole, and reducing mitral regurgitation. However, little is known of the mechanisms of BVP in heart failure patients with drug-resistant chronic atrial fibrillation. HYPOTHESIS AND METHODS: LVP differs from BVP because hemodynamic and clinical improvement occurs in association with prolongation rather than shortening of the QRS duration. We sought to determine if LVP or BVP improves mechanical synchronization in the presence of atrial fibrillation. Thirteen patients with chronic atrial fibrillation, severe heart failure and QRS >or=140 ms received (after His bundle ablation) a pacemaker providing both LVP and BVP. The mean age was 62 +/- 6 years and left ventricular ejection fraction was 24 +/- 8%. After a baseline phase of one month with right ventricular pacing, all patients underwent in random order 2 phases of 2 months (LVP and BVP). At the end of each phase, an echocardiogram, a hemodynamic analysis at rest and during a 6-minute walking test and a cardio-pulmonary exercise test were performed. RESULTS: LVP and BVP provided similar performances at rest (p = ns). The 6-minute walking test revealed similar performances in both pacing modes but patients were significantly more symptomatic at the end of the test with LVP ( p = 0.035). The cardio-pulmonary exercise test showed higher performances with BVP (92 +/- 34 Watts) vs. LVP (77 +/- 23; p = 0.03). LVP was associated with significantly more premature ventricular complexes recorded during the 6 minute walking test (49 +/- 71) than BVP (10 +/- 23; p = 0.04). CONCLUSIONS: In this small series of patients with atrial fibrillation, congestive heart failure and a prolonged QRS duration, LVP and BVP provided similar hemodynamic effects at rest whereas BVP was associated with better hemodynamic effects during exercise and fewer premature ventricular complexes. Although the mechanisms for the observed differences are uncertain, it is possible that there is worsening of right ventricular function due to a rise in left-to-right electromechanical delay during exercise. Increased catecholamines release might contribute to the lower exercise tolerance and greater number of premature ventricular complexes recorded during exercise observed during LVP compared to BVP. RECOMMENDATIONS: Patients with atrial fibrillation, heart failure and QRS prolongation who are candidates for His-bundle ablation and cardiac resynchronization therapy may respond better to BVP rather than to LVP.

Atrial Fibrillation↗