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Introduction: The peak of endocardial acceleration (PEA) is an index of myocardial contractility. We aimed to (1) demonstrate that the PEA measured by the noninvasive cutaneous precordial application of an accelerometer sensor is related to left ventricular (LV) dP/dt max and (2) assess the usefulness of PEA monitoring during graded ischemia and during different configurations of sequential biventricular pacing., Methods and Results: Measurements of invasive LV dP/dt max were compared with measurements of transcutaneous PEA in seven pigs at baseline and during acute drug infusions; increased heart rate; right, left, biventricular and sequential biventricular pacing before and after graded ischemia induced by the constriction of the left anterior descending coronary artery. A consistent PEA signal was obtained in all animals. PEA changes were highly related to LV dP/dt max changes (r= 0.93; P < 0.001). The changes of LV contractility induced by the different pacing configurations were detected by PEA analysis in the absence of ischemia (r= 0.94; P < 0.001) and in the presence of ischemic LV dysfunction (r= 0.91; P < 0.001)., Conclusion: Noninvasive PEA measurement allows monitoring of left ventricular contractility and may be a useful tool to detect global effect of ventricular ischemia and to optimize the choice of both pacing site and pacing configuration.

We report the case of a 60-year-old patient with preserved ventricular function and no organic mitral leaflet disease implanted with a dual-chamber pacemaker. Right ventricular pacing induced a major ventricular dyssynchrony, a severe mitral regurgitation, and symptoms of congestive heart failure. Upgrading to a biventricular device was associated with a decrease in the symptoms, the ventricular dyssynchrony, and the mitral regurgitation.

Background: Cardiac resynchronization therapy (CRT) is recommended in patients with ejection fraction <35%, QRS width> 120 ms, and New York Heart Association (NYHA) functional class III or IV despite optimal medical therapy. We aimed to define demographic, clinical, and electrocardiographic predictors of positive clinical response to CRT., Methods and Results: Hundred consecutive patients fulfilling the recommended criteria were implanted with a CRT device. Demographic, clinical, two-dimensional echocardiographic and electrographic parameters were measured at baseline and after 6 months of simultaneous biventricular pacing. A positive response to CRT included an improvement of at least one NYHA functional class associated with an absence of hospitalization for worsening heart failure. At the end of follow-up, 12 patients were dead and 71% of the patients were classified as responders. After 6 months of CRT, the ejection fraction was significantly higher (P = 0.035) in responders versus nonresponders. Multivariate analysis identified three independent predictors of positive response to CRT: an idiopathic origin of the cardiomyopathy (P = 0.043), a wider QRS before implantation (P = 0.017), and a narrowing of the QRS after implantation (P = 0.037)., Conclusion: An idiopathic origin of the cardiomyopathy, a wider QRS before implantation, and a narrowing of the QRS width after implantation were identified as independent predictors of clinical positive response to CRT.

Introduction: Radiofrequency (RF) ablation of the cavotricuspid isthmus (CTI) can be performed using different types of ablation catheter. Gold tip electrodes have the theoretical advantage of creating bigger lesions than standard platinum-iridium electrode. This prospective, randomized study compares the clinical efficacy of 8-mm gold tip catheter, externally irrigated and 8-mm platinum-iridium tip (Pt tip) catheters., Methods and Results: Sixty consecutive patients (51 men, 60 +/- 10 years) undergoing de novo CTI ablation for documented typical atrial flutter were randomized to one of the following ablation catheters: 8-mm gold tip catheter, an externally irrigated-tip (Irr. tip) catheter, or an 8-mm Pt tip catheter. The procedural endpoint was achievement of bidirectional isthmus conduction block with < or = 20 minutes of RF energy application. The latter was achieved equally with the 3 catheters (95% for gold tip, 100% for irrigated tip, 95% for Pt tip) and the durations of RF (10 +/- 6, 10 +/- 4, 13 +/- 8 minutes), fluoroscopy (12 +/- 6, 12 +/- 7, 15 +/- 12 minutes) and the procedure (34 +/- 23, 38 +/- 24, 40 +/- 30 minutes) were similar in all groups. The maximal targeted power could not be reached in at least one location in 40% of patients with gold tip and in 35% of patients with Pt tip catheters whereas it was always achieved with an Irr. tip catheter (P = 0.003, P = 0.008). The reduction in impedance during RF delivery was greater with Irr. tip (11 +/- 7 ohms) than with gold (7 +/- 4 ohms, P = 0.02) or Pt tip (5 +/- 3 ohms, P = 0.001) catheters., Conclusion: This study demonstrates equivalent efficacies of gold, platinum-iridium and externally Irr. tip catheters for successful de novo ablation of the CTI.

Arrhythmias are more frequent in patients with sleep apnea syndrome. Bradycardias predominate. In the absence of controlled studies, it is difficult to link arrhythmias to sleep apnea syndrome or to the disease accompanying it (coronary disease, hypertension, etc.). Continuous positive airway pressure (CPAP) reduces arrhythmias significantly.

The search for a mechanism to explain atrial fibrillation (AF) has lasted for over a century and continues. Significant progress in understanding this arrhythmia accelerated with the era of operative treatment of this arrhythmia and intensified with the advent of catheter ablation. Through considerable trial and some error, effective "curative" therapies have evolved for paroxysmal AF and are evolving for persistent AF. It is becoming clear that no single mechanism suffices to explain AF in all its forms and multiple mechanisms are playing a role in the most complicated cases.

Background: The incidence of endocarditis related to pacemakers is increasing, while the diagnosis and management remain difficult. The objective of this study was to evaluate the clinical features and management of endocarditis after implantation of pacemakers (PM) or cardioverter defibrillators (ICD)., Methods: We analyzed the hospital course of 60 consecutive patients (48 men, mean age 68 +/- 12 years) admitted to our center for PM (n = 59) or ICD (n = 1) endocarditis between 1998 and 2004., Results: Fever (78%), asthenia (65%), and local symptoms (35%) were common. Positive cultures were obtained in 53 cases (Staphylococcus 89%). Sixteen patients (27%) had pulmonary embolism. Vegetations (mean size 15.2 +/- 8 mm, range 5 to 35 mm) were found in 54 cases (90%), with transthoracic echocardiography in 26 cases (43%), and transesophageal echocardiography (TEE) in 50 cases (89% of the 56 patients who had TEE). Devices were removed surgically (n = 20) or percutaneously (n = 37). In the surgical group, vegetations were larger (17.9 +/- 7 mm vs 13.2 +/- 7 mm, P = 0.01). After removal, 42 patients (70%) had a new PM. Mortality factors (6 deaths - follow up 3.4 +/- 2 years) were the number of vegetations and absence of extraction of the device (P < 0.02). Clinical features and management of the 37 patients with early onset endocarditis (within 1 year after implantation) did not differ from those with late onset., Conclusions: PM endocarditis was essentially staphylococcal. TEE was required for the diagnosis of vegetations. Complete removal of the device is required and associated with a favorable outcome.

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.

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).

Background: Pulmonary vein (PV) isolation and linear lesions are effective in eliminating paroxysmal atrial fibrillation (AF), but linear lesions probably are not required in all patients. Noninducibility of AF has been shown to be associated with freedom from arrhythmia in 87% of patients., Objectives: The purpose of this study was to prospectively evaluate the role of noninducibility in guiding a stepwise approach tailored to the patient., Methods: In 74 patients (age 53 +/- 8 years) with paroxysmal AF, PV isolation was performed during induced or spontaneous AF. If AF was inducible after PV isolation, one to two additional linear lesions were placed at the mitral isthmus and/or left atrial roof, with the endpoint of noninducibility of AF or atrial flutter. Inducibility (AF/atrial flutter, lasting > or = 10 minutes) was assessed using burst pacing at an output of 20 mA down to refractoriness from the coronary sinus and both atrial appendages., Results: In 42 patients (57%), PV isolation restored sinus rhythm and rendered AF noninducible. In the 32 patients with persistent or inducible AF after PV isolation, a single linear lesion achieved noninducibility in 20, whereas two linear lesions were required in 12 and resulted in conversion to sinus rhythm and noninducibility in 10. Using this stepwise approach, a total of 69 patients (93%) were rendered noninducible. During follow-up of 18 +/- 4 months, 67 patients (91%) were free from arrhythmia without antiarrhythmic drugs. Repeat procedures were performed in 23 patients: repeat ablation was required to consolidate prior targets in 15 patients (20%), and "new" linear lesions, which were not predicted by inducibility during the index procedure, were required in 8 (11%)., Conclusion: Noninducibility can be used as an endpoint for determining the subset of patients with paroxysmal AF who require additional linear lesions after PV isolation. This tailored approach is effective in 91% of patients while preventing delivery of unnecessary linear lesions.

Background: Noninducibility of sustained atrial fibrillation (AF) after pulmonary vein isolation (PVI) has been shown to be associated with a better clinical outcome. We evaluated the role of clinical variables that could predict noninducibility of sustained AF after PVI., Methods and Results: Data were collected prospectively from 181 patients (153 male; age 54 +/- 9 years) referred for ablation of drug-refractory symptomatic paroxysmal AF (duration < or =7 days). Clinical variables were evaluated with regard to their ability of predicting noninducibility of sustained AF (< or =10 minutes) after PVI. Univariate analysis was performed on all collected variables followed by multivariate analysis for variables showing a P value <0.1. After PVI, sustained AF was noninducible in 97 (54%) patients. The following clinical variables showed a significant difference between the groups: body weight, longest AF episode, duration of AF history, presence or absence of structural heart disease, left ventricular (LV) hypertrophy, prior cardioversion, left atrial (LA) parasternal, and longitudinal diameters and LV diameters. On multivariate analysis, three independent predictors of noninducibility were identified: a shorter duration of AF episodes (AF <12 hours: RR 0.01 (0.002-0.06), P < 0.001; AF 12-48 hours: RR 0.07 (0.01-0.37), P = 0.001); LA longitudinal diameter <57 mm (RR 0.33 (0.13-0.82), P = 0.016); and absence of LV hypertrophy (RR 0.15 (0.04-0.63), P = 0.01)., Conclusions: Shorter AF episodes, smaller LA longitudinal diameter, and absence of LV hypertrophy are independent predictors of noninducibility of sustained AF after PVI.

Aims: Catheter ablation of atrial fibrillation (AF) is centred on pulmonary vein (PV) ablation with or without additional atrial substrate modification. These procedures may be prolonged with significant fluoroscopy exposure. This study evaluates a new non-fluoroscopic navigation system during ablation of AF., Methods and Results: Seventy-two patients undergoing catheter ablation of symptomatic drug refractory AF were prospectively randomized to ablation with (n=35; study group) or without (n=37; control group) non-fluoroscopic navigation. PV isolation was performed in all patients. In patients with persistent or inducible sustained AF after PV isolation linear ablation was performed by joining the superior PVs. PV isolation was achieved in all patients; fluoroscopy (15.4+/-3.4 vs. 21.3+/-6.4 min; P<0.001) and procedural (52+/-12 vs. 61+/-17 min; P=0.02) durations were significantly reduced in the study group. Linear block was achieved in 37 of the 39 patients; with a significant reduction in fluoroscopy (5.6+/-2.2 vs. 9.9+/-4.8 min; P=0.003) and procedural (14.7+/-5.5 vs. 26.6+/-16.9 min; P=0.007) durations in the study group. After a follow-up of 6.9+/-2.9 months (range 3-10), 26 (74%) patients in the non-fluoroscopic navigation group and 29 (78%) patients in the control group were arrhythmia-free after the first procedure., Conclusion: This prospectively randomized study demonstrates significant reduction of fluoroscopy exposure and procedural duration using supplementary non-fluoroscopic imaging system for AF ablation.

Unlabelled: In patients with congenital heart block (CHB), dual-chamber pacing restores physiological heart rate and atrio-ventricular synchronization. However, patients with narrow QRS junctional escape rhythm may be deleteriously affected by long-term, permanent, apical ventricular pacing. We assessed the impact of apical ventricular pacing on echocardiographic ventricular dyssynchrony and hemodynamic parameters., Methods: Fourteen CHB adults (23 +/- years, 58% male), with a DDD transvenous pacemaker and a junctional escape rhythm (QRS<120 ms) before implantation, were studied. Echocardiography coupled with tissue Doppler imaging (TDI) and Strain rate was performed in spontaneous rhythm (VVI mode 30/mn) and during atrio-synchronized ventricular pacing., Results: The heart rate (43 +/- 09 vs 68 +/- 07: p<0.01), cardiac output (2.9 +/- 0.7 vs 3.7 +/- 0.6 L/min) and left ventricular filling time (325 +/- 38 vs 412 +/- 51 ms; p<0.01) were significantly less in the escape spontaneous rhythm compared with atrio-ventricular synchronized apical pacing. However, interventricular dyssynchrony (28 +/- 12 vs 59 +/- 25 ms, p<0.05), intra-left ventricular dyssynchrony (36 +/- 11 vs 57 +/- 29 ms; p<0.05), extent of left ventricular myocardium displaying delayed longitudinal contraction (26 +/- 10 vs 39 +/- 17%: p<0.05) were significantly less in the escape rhythm compared with paced rhythm., Conclusion: Once implanted with a DDD pacemaker, CHB patients present with increased cardiac output secondary to the restoration of physiological heart rate and improved diastolic function. However, the apical site is not optimal, as it creates detrimental ventricular dyssynchrony in patients with previous nearly physiological ventricular activation. Alternative pacing sites should be investigated.

Advances in echocardiography have paved the way for the development of intracardiac catheters with ultrasound transducers mounted on its tip. With this technology it has become possible for the interventional electrophysiologist to perform continuous echocardiographic examination during a procedure without the need for general anaesthesia or additional staff. Intracardiac echocardiography (ICE) allows the monitoring of catheter movement in real-time, assessment of catheter-tissue contact and potentially prevents and recognizes complications like thrombus formation and pericardial effusion. In addition recent technologies allow acquiring the full spectrum of Doppler-imaging permitting evaluation of haemodynamic data during the procedure. All these advances have made ICE an ideal tool for the interventional electrophysiologist, serving as a diagnostic and imaging tool during invasive electrophysiological procedures. This review will summarize currently available technology of ICE and its indications and applications in electrophysiological procedures.

Primary hyperaldosteronism is a diagnosis which should be considered in refractory hypertension even in the absence of any hypokalaemia. Its detection relies above all on the levels of renin and aldosterone. The aldosterone/renin ratio has been proposed as the most sensitive criterium. The reference values used for the diagnosis of primary hyperaldosteronism are very variable in the literature, depending not only on the method used but also on the criteria used for their determination. In this study we evaluated the defined reference values prospectively by studying a population of patients with a Conn's adenoma treated surgically. The study included an initial retrospective period which allowed identification of 29 cases of Conn's adenoma treated surgically, and a 9 month prospective period during which 212 reports were collected. During this prospective period a further 9 cases of Conn's adenoma were detected, which were successfully treated with surgery. Analysis to discriminate the 38 Conn's adenomata from the rest showed that 3 parameters contributed significantly and independently to the diagnosis: supine plasma renin activity (ARPc), supine aldosteronaemia and the erect aldosterone/renin ratio, allowing correct classification in 88% of the cases. The reference ranges of these 3 parameters were calculated in order to give a sensitivity of 100% and the best possible specificity, therefore allowing a combined criterium involving all 3 parameters to be defined: ARPc < 0.45 ng/ml/h, supine aldosteronaemia >417 pmol/l, and erect aldosterone/renin >1180.

Objectives: The purpose of this study was to evaluate a possible correlation between atrial ECG amplitude in common atrial flutter (AFL) and radiofrequency (RF) energy required to achieve cavotricuspid isthmus block., Background: The amount of RF delivery required for ablation of typical AFL is variable. This variation has been attributed to the cavotricuspid isthmus anatomy. Atrial ECG amplitude can be a marker of atrial anatomic variations and therefore may correlate with RF duration required to achieve cavotricuspid isthmus block., Methods: Seventy consecutive patients were prospectively studied. Ablation of the cavotricuspid isthmus was performed by creating a line of block between the inferior tricuspid annulus and the inferior caval vein using 8-mm-tip electrode catheters. If more than 20 minutes of RF time was required to achieve conduction block, the catheter was changed to an irrigated-tip catheter. Atrial ECG amplitude was assessed in leads II, III, aVF, and aVL., Results: A total of 14 +/- 11 minutes of RF energy was delivered to achieve block in all patients; 12 patients (8%) required more than 20 minutes. Atrial ECG amplitude showed highly significant correlations with cumulative RF energy (F and P waves in lead II: r = 0.703 and r = 0.737, P < .001). P-wave amplitude <0.2 mV and/or flutter wave amplitude <0.35 mV in lead II have a high negative predictive value to predict <20 min RF delivery (96% and 89% respectively)., Conclusions: A significant correlation exists between atrial ECG amplitude and amount of RF required to ablate typical AFL. Atrial ECG amplitude may be a surrogate marker of characteristics of isthmus anatomy. These findings may influence the choice of catheter used for cavotricuspid isthmus ablation.

Home monitoring (HM) of cardioverter defibrillators (ICD) with its automated wireless remote data access, may decrease the rate of patient visits. This study examined the potential cost savings for the long-term care of ICD assisted by HM. A French database including 502 patients from 6 university hospitals was used. Costs of conventional follow-up (FU) of ICD were calculated without, and compared with the expected cost of FU with HM. Calculations included number of visits, including physician's fees, electrocardiograms, and specific ICD surveillance, and transportation costs. The mean distance between home and institutions performing follow-ups was 69 +/- 57 km. For each visit, a mean overall cost of 215 dollars was calculated, including 121 dollars for transportation and 94 dollars for medical services. HM may obviate up to 2 visits per year. Over the 5 years of expected life of the device, the decrease in costs for FU visits was estimated at 2,149 dollars. With an additional cost of 1,200 dollars for the HM system, saving began after a mean FU of 33.5 months. The time to onset of cost saving by HM ranged between 17.4 months for patients living >150 km from the medical facility to 52.2 months for those living <50 km away. It is concluded that the HM may considerably reduce the overall costs of ICD FU by saving on transportation cost, particularly when the distance between home and medical facility is >100 km.

Atrial fibrillation, the most common cardiac arrhythmia, is frequently disabling and drug-resistant, and can be associated with major complications such as thromboembolic events. Non drug approaches, including surgery and catheter-based ablation, are used to treat the most severely symptomatic patients. These new treatment strategies have drastically improved our knowledge of the pathophysiology of this arrhythmia and, importantly, have shown that atrial fibrillation is curable. Since 1994, two main approaches have been used to modify the substrate responsible for AF maintenance, namely the creation of linear lesions, and ablation of triggers located within the pulmonary veins (about 90% of cases). Most teams worldwide now use approaches centered on PV isolation, which, although imperfect, are sufficiently effective to be offered routinely to selected patients in experienced centers. The importance of PVs in the initiation of AF has been clearly demonstrated, and there is also evidence of a role in AF maintenance. However, the existence of non venous foci or a prominent substrate for AF maintenance limits the success rate to about 70%. We are now using a combination of PV isolation and a linear lesion delivered to the mitral isthmus, from the mitral annulus to the ostium of the left inferior pulmonary vein. This more complex procedure carries a significantly higher success rate, about 82% of patients being cured and drug-free. The main problem is to identify patients requiring mitral isthmus ablation in addition to PV isolation. At present, AF ablation is restricted to symptomatic patients in whom at least two antiarrhythmic drugs have failed, but future technical improvements are likely to broaden the indications of ablation therapy for AF.

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.

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.

Background: Radiofrequency (RF) ablation of cavotricuspid isthmus (CTI) dependent flutter can be performed using different types of ablation catheters. It has been proposed that irrigated and large-tip catheters are capable of creating larger lesions, resulting in greater efficacy. This prospective, randomised clinical study compared the efficacy of irrigated and large-tip catheters of different designs., Methods: Eighty patients (69 men, 66+/-11 years) undergoing de novo RF ablation of CTI-dependent flutter were randomised to ablation using one of the following catheters: (i) externally-irrigated 20), (ii) internally-cooled (n=20), (iii) single sensor, 8-mm tip (n=20), or (iv) double sensor, 8-mm tip (n=20). The study endpoint was the demonstration of bidirectional CTI conduction block within 12 min of cumulative RF delivery. Crossover to the externally-irrigated catheter was permitted if this was not achieved. The ablation and procedural parameters, safety and efficacy were compared., Results: The primary endpoint was achieved in 64 patients (80%), including all 20 patients randomised to the externally-irrigated catheter. Crossover was required in 16 patients: 9 initially using the internally-cooled catheter (45%), 3 using single-sensor, 8-mm-tip (15%), and 4 using double-sensor, 8-mm-tip (20%) catheters. The higher initial failure rate with the internally-cooled-tip catheter was significant compared to the externally-irrigated (p = 0.001) and single-sensor, 8-mm-tip (p = 0.04) catheters. The externally-irrigated catheter achieved the study endpoint more frequently with fewer RF applications of shorter duration compared to the internally-cooled-tip catheter and 8-mm-tip catheters, the difference being significant compared with internally cooled ablation. No major complications were observed., Conclusion: Among commonly used ablation catheters, the externally-irrigated catheter has a higher efficacy for rapid achievement of CTI block.

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.

One could expect that malignant hypertension would belong to the history. Unfortunately, this complication has not been eradicated even though many physicians have already forgot it. The hypertension care units are still confronted to it, and even the arrival of the renin-angiotensin system blockers have changed the prognosis of those patients, an adequate management on emergency remains mandatory in order to avoid in particular the evolution to renal failure. By reporting a series of 42 patients included in a period of 7 years, we aimed to remind the presentation of this severe pattern of hypertension and the basics of its management.

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.

In the general adult population, prevalence of sleep apnea syndrome reaches 4% in men and 2% in women. Continuous positive airway pressure is the most efficient treatment. At the present time, although severe atrial bradycardias could occur during sleep apnea episodes, cardiac pacing has not been demonstrated as an efficient treatment for those bradycardias. Treating sleep apnea generally reduces the number of bradyarrhythmias. However, recent studies reported a beneficial effect of atrial pacing on the sleep apnea burden. The mechanisms rely on two phenomena: first to counteract nocturnal hypervagotonia, and second to treat heart failure. By increasing the heart rate, cardiac output improves, which mitigates pulmonary subedema. Consequently, stimulation of the pulmonary afferent vagal fibers is diminished, which reduces central sleep apnea incidence. During nocturnal hypervagotonia, snoring and obstructive apnea episodes are increased, mainly due to an excessive muscular relaxation of the upper airway area inducing cyclical substantial decreases in the airway caliper. In patients with a low heart rate, atrial pacing can counteract hypervagotonia by enhancing the sympathetic tone and modifying the degree of vigilance. Accordingly, in the near future, sleep apnea treatment might potentially rely on atrial pacing in bradycardic patients with hypervagotonia (with or without heart failure). The role of the physician would then be not only to diagnose sleep apnea, but also to identify potential responders to cardiac pacing.

Objectives: We sought to assess the electromechanical parameters, using tissue Doppler echocardiography, as potential independent predictors of heart failure (HF) worsening., Background: Ventricular conduction disorders worsen the prognosis for HF patients. However, the relationships between the QRS width and morphology, hemodynamic parameters, and presence and magnitude of intra-left ventricular (LV) and inter-ventricular (V) asynchrony have not been well clarified., Method: A total of 104 patients with an LV ejection fraction (EF)

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.

RF catheter ablation of paroxysmal atrial fibrillation (PAF) is associated with prolonged fluoroscopy. The procedural duration and fluoroscopic exposure to patients and medical staff were recorded and compared among 43 ablation procedures for PAF, 20 for common atrial flutter, and 16 for accessory pathways. Patient radiation exposure was measured by dosimeters placed over the xyphoid, while that of physicians and nurses was measured by dosimeters placed outside and inside the lead apron. The mean fluoroscopy time was 57 +/- 30 minutes for PAF, 20 +/- 10 minutes for common flutter, and 22 +/- 21 minutes for accessory pathway ablation. The patient median radiation exposure was 1110 microSv for PAF, compared with 500 microSv for common flutter and 560 microSv for accessory pathway ablation (P < 0.01). The median radiation exposure to physician and nurse inside the lead apron were, respectively, 2 microSv and 3 microSv for PAF, 1 microSv and 2 microSv for common flutter, and < 0.5 microSv and 3 microSv for accessory pathway ablations. RF catheter ablation for PAF was associated with prolonged fluoroscopy times and a twofold higher radiation exposure to the patient and physician compared with other ablation procedures. Assuming 300 procedures/year, radiation exposure to the medical staff was below the upper recommended annual dose limit.

Although it has been suggested that multisite ventricular pacing alleviates heart failure by restoring ventricular electrical synchronization, the respective roles of voltage output, interventricular delay, and pacing sites in the development of ventricular arrhythmias occurrence have not been studied during biventricular pacing or LV pacing. Voltage-sensitive dye was used in eight ischemic Langerdorff-perfused guinea pig hearts to measure ventricular activation times and examine conduction patterns during multisite pacing from three RV and four LV sites. The hearts were stained with di-4-ANEPPS and mapped with a 16 x 16 photodiode array at a resolution of 625 microns per diode. Isochronal maps of RV and LV activation were plotted. Ischemia was produced by gradually halving the perfusion output over 5 minutes. Pacing the RV apex and the base of the LV anterior wall was associated with the most homogeneous and rapid activation pattern (28 +/- 9 vs 41 +/- 12 ms with the other configurations, P < 0.01), and no inducible arrhythmia. In six hearts, ventricular tachycardia could be induced when pacing from the right and left free walls with 20 ms of interventricular delay, at six times the pacing threshold output. In four hearts, simultaneous RV and LV pacing at high voltage output induced ventricular fibrillation with complex three-dimensional propagation patterns, independently of the pacing sites. During biventricular pacing with ischemia, pacing at high voltage output with a long interventricular delay is likely to induce ventricular arrhythmias, particularly when left and right pacing results in a conduction pattern orthogonal to the ventricular myocardial fibers orientation.

Objectives: This study evaluated the use of ectopic P-wave morphology to localize pulmonary vein (PV) and non-PV sources of atrial ectopics in patients with paroxysmal atrial fibrillation (PAF)., Background: The vectorial information embodied in the morphology of ectopic P waves is concealed by overlying T waves., Methods: The P-wave morphology of 56 ectopics was prospectively analyzed in 44 patients with PAF (age, 52 +/- 12 years; 36 male) by subtracting the adjacent QRST from the QRST-ectopic P-wave complex using custom-designed software. Subtraction fidelity was validated in 15 other patients (55 +/- 19 years, 11 male) by comparing drive beats with simulated ectopics (S2 from the same site) unmasked by subtracting overlying QRST. An algorithm combined with PV pacemaps was used to predict PV sources. Subtracted ectopic P-wave morphologies after PV disconnection were compared with PV and non-PV site pacemaps. Localization was confirmed by mapping and successful ablation., Results: A > or =10-lead electrocardiogram (ECG) match was observed in 92% of 644 simulated ectopics (coupling intervals: 190 to 520 ms). In PAF patients, 37 spontaneous ectopics originated from the PV, while 19 were noted after PV disconnection. Using the P-wave algorithm alone, correct prediction of PV origin was achieved in 30/37 ectopics (81%). Combination with PV pacemaps allowed correct prediction in 34/37 (92%). After PV disconnection, ECG localization predicted successful ablation sites in 16/19 (84%)., Conclusions: Comparison of subtracted ectopic P waves with a pacemap catalogue provides a simple and accurate 12-lead ECG-based method for localization, which can facilitate ablation of arrhythmia triggers irrespective of origin from the PV or elsewhere.

In the Bordeaux cohort of never treated, uncomplicated hypertensive patients with office BP > 140/90 on at least 2 occasions, we selected those with good quality 24 H ambulatory BP measurement and LVM measured with M mode echo before any antihypertensive treatment. In this group, we studied the relationships between LVM and average 24 h systolic BP in males and females in univariate and multivariate analysis, taking into account age, weight and height. The population studied included 531 patients whose main characteristics are summarized in the table. The slope of the relationship between LVM and 24 h SBP is significantly steeper in males than in females (1.73 vs 0.58, p < 0.01). In multivariate analysis, the variable showing the higher correlation to LVM is 24 h SBP in males, weight in females. For a similar increase in BP, males hypertensive show a higher increase in LVM than females.

Background: Despite extensive proximal ablation, all potentials frequently cannot be eliminated from the left pulmonary veins (PV). Methods and Results- PV electrograms were analyzed during sinus rhythm, coronary sinus, and left atrial appendage (LAA) pacing, and PV and LAA angiography performed. During pacing, an initial low-amplitude slow potential was recorded on the anterior aspect of the left superior PV and anticipated with shortest activation time by LAA pacing. Its timing coincided with posterior LAA activation, shown to be immediately adjacent to the left superior PV by angiography. In the left inferior PV, the first potential was smaller and less sharp, coinciding with adjacent low LA activation. Angiographically, the LAA was at least 15 mm from the left inferior PV. The second sharper potential in both left PVs was eliminated by proximal ablation., Conclusion: Far field LAA activity consistently adds to PV myocardial electrograms in the left superior PV whereas lower, less sharp extravenous potentials in the left inferior PV originate from the inferior LA. They can be identified by LAA and coronary sinus pacing.

The rate responsiveness of a single chamber, accelerometer-based pacemaker with an autocalibration function (Opus G VVIR pacemaker, ELA Medical) was studied with a daily life protocol developed to automatically optimize the programming of accelerometer-based sensors. This new sensor was compared with two other body activity sensors that were manually optimized patient by patient. Forty-three pacemaker recipients (mean age 71 +/- 11 years), paced > 95% of the time, underwent a daily life protocol consisting of rapid walking for 6 minutes (W), climbing upstairs for 1.5 minutes (U), and downstairs for 1.5 minutes (D), alternated by recovery phases. The results were compared with performances measured in a control population of healthy subjects and in two paced patient populations (one equipped with a Dash Intermedics VVIR pacemaker and the other equipped with a Sensolog III Pacesetter/St. Jude VVIR pacemaker). Sex distribution and mean age between paced patients and control subjects were statistically comparable. The mean heartrate achieved by all paced patients at each time sample was compared with the normograms, assigning acceleration (slope) and rate (rate) scores for exercise and recovery phases. Scores ranged from -10 (hypochronotropic) to +10 (hyperchronotropic). Zero represents exact concordance with the responses of healthy individuals, and values between -2.5 and +2.5 were considered statistically similar to normal. During W, although the overall performances of the Dash, Sensolog, and Opus G did not statistically differ from healthy controls, the scores obtained by the Opus G were significantly closer to controls than those of the two other pacemakers (P = 0.02). For U, the three sensors were hypochronotropic (P = 0.03), though the Opus G was associated with a heart rate response closer to that of healthy controls (P = 0.04). D provided similar mean heart rate scores for the Opus G and the Dash compared with healthy controls, in contrast with the hyperchronotropic behavior of the Sensolog (P = 0.02). Opus G revealed a physiological modulation of the heart rate for W and D tests with a slightly hypochronotropic behavior during U. The Opus G autocalibration function provided daily life performances closer to those of healthy controls than two other pacemakers equipped with a body activity sensor that were manually optimized.

Left ventricular hypertrophy (LVH) is associated with an increased risk of cardiovascular complications independently of other known risk factors. Since 1983, we have followed up a cohort of initially untreated hypertensive patients with echocardiographic measurements of left ventricular mass (LVM). We analyzed the data on 474 patients with more than five years' follow-up to assess the prognostic value of LVM and the sensitivity and specificity of the different ways to index for LVM through ROC curves. Forty patients were lost to follow-up. The mean follow-up period was 89 +/- 31 months. A cardiovascular complication was recorded in 40 individuals. There was a strong link between increased LVM and the occurrence of complications. Indexation by body surface area or height to the power 2.7 give the [table: see text] greatest area under the curve (AUC) to discriminate between patient with or without cardiovascular events. To get the same sensitivity in females and in males for the prediction of future events, lower cut-off must be used in females.

The implantation of permanent pacemakers in patients with congenital heart disease can be challenging. This report describes the complexity of pacemaker implantation in a patient with Ebstein's disease, tricuspid valve replacement, and right atrial abnormalities like severe intra- and interatrial conduction block that prevented dual chamber pacing from conventional sites. This case illustrates the promising possibility to circumvent the interatrial conduction block with single left atrial pacing instead of biatrial pacing which was not suitable here.

Left ventricular hypertrophy (LVH) is associated with an increased risk of cardiovascular complications independently of other known risk factors, but so far the predictive value of its evolution under treatment has been studied relatively little. Since 1983 we have followed up a cohort of initially untreated hypertensive patients with echocardiographic measurements of left ventricular mass (LVM). We analyzed the data on 474 patients with more than 5 years of follow-up to assess the prognostic value of LVM and its evolution during treatment for high blood pressure. A total of 40 patients were lost to follow-up. The mean follow-up period was 89 +/- 31 months. A cardiovascular complication was recorded in 40 individuals. There was a strong link between increased LVM and the occurrence of complications (P < .001). At least a second determination of LVM was performed in 311 patients, and the last value before the occurrence of any complication (60 +/- 38 months after the initial examination) was retained. In this subgroup, 28 patients presented with a cardiovascular event. There was a trend toward a reduction of the incidence of events in the group with a regression of LVH as compared to the group with persistent LVH, but there was no difference when patients were split into quartiles according to LVM evolution between baseline and follow-up. Thus, the reduction of LVM on treatment was not a good marker of future cardiovascular events and its seems at least premature to say that LVM fulfils all conditions for a surrogate end point in the evaluation of morbidity/ mortality in the hypertensive.

Background: Reduced distensibility of large arteries plays an important role in cardiovascular risk. Determination of the QKD interval during the ambulatory measurement of blood pressure enables calculation of an index of arterial distensibility. This index, the QKD(100-60), is the theoretical value of QKD at systolic blood pressure of 100mmHg and heart rate of 60bpm obtained from the linear bivariate relationship linking QKD, systolic blood pressure and heart rate on a hundred successive values measured over 24h. This study was designed to examine the relationship between QKD and QKD(100-60) on heart rate and systolic function of the left ventricle, the two parameters governing the pre-ejection time which is part of the QKD interval., Methods and Results: In a population of 203 untreated hypertensive patients having benefited from an ambulatory measurement of blood pressure over 24h with QKD monitoring and an M-mode echocardiographic recording of the left ventricle, we found that although mean QKD was linked to heart rate and systolic function of the left ventricle, QKD(100-60) was not. It fell significantly with age, and to a greater extent in the sustained hypertensives than in white-coat hypertensives., Conclusion: QKD(100-60) constitutes an index of arterial distensibility independent of the pre-ejection time. As an adjunct to the ambulatory measurement of blood pressure, its determination is simple and completely automatic, thus eliminating observer bias.

Multisite ventricular pacing acutely improves the hemodynamic status in heart failure, though longer-term observations require invasive procedures. The hemodynamics of multisite ventricular pacing were assessed by echocardiography and peak endocardial acceleration (PEA) measured by a pacemaker sensor. PEA variations are highly correlated with those of dP/dt. Thirteen end-stage heart failure patients (left ventricular ejection fraction < 0.30) with a QRS > or = 140 ms received a DDD PEA sensor-driven pacemaker allowing right (RV), left (LV) and biventricular (BV) pacing. Ten days after implantation, standard echocardiographic parameters and variations in PEA were measured after 20 minutes at each pacing mode. The aortic systolic preejection time interval was statistically comparable between RV and LV pacing (218 +/- 24 vs 219 +/- 34 ms; P = NS), and significantly shorter with BV pacing (198 +/- 27 ms; P = 0.013). Aortic ejection duration was nonsignificantly shorter during BV pacing than during LV pacing (-.061, P = 0.09). The aortic velocity time integer increased during LV pacing versus RV pacing (+21%, P < 0.05) and during BV pacing versus RV pacing (+37%, P = 0.05). As a result, the values of the PEA variations over a 15-minute period were significantly greater during LV pacing and BV pacing versus RV pacing (+43%, P < 0.05, and +38%, P = 0.05, respectively) and were statistically comparable between BV pacing and LV pacing (9% for LV pacing, P = NS). During various ventricular pacing configurations, PEA measurements were consistent with echocardiographic data, showing comparable hemodynamic effects of BV and LV pacing. The PEA sensor is a promising tool for long-term hemodynamic monitoring and serial evaluation of the effects of multisite ventricular pacing in heart failure patients.

In a patient with severe congestive heart failure and ischemic disease, frequent episodes of ventricular tachycardia were completely suppressed by an implantable cardioverter defibrillator with biventricular pacing.

Biventricular (BV) pacing acutely improves the hemodynamic status of patients with chronic heart failure (CHF) and wide QRS complex. Long-term data are few. This study examined the relationship between hemodynamic and clinical status of BV-paced CHF patients over an intermediate duration of follow-up. Forty-seven patients (mean age 64 +/- 11 years, 19% women, LVEF 0.23 +/- 0.07) with QRS > or = 140 ms received a DDD-BVP device for management of CHF due to ischemic disease in 21 (45%) patients. Clinical, electrocardiographic, exercise testing, and hemodynamic measurements were followed over an 8-month period. Seven patients died during the study, four patients suddenly. A significant decrease in NYHA class, from 3.3 +/- 0.6 before implantation, to 2.5 +/- 0.57 months after device implantation (P < 0.01) was measured, although 23% of patients reported no symptomatic improvement. Paced QRS narrowing by BVP was unchanged throughout follow-up (166 +/- 28 vs 159 +/- 23 ms, P = NS). Maximal VO2 values did not change (15.7 +/- 5 vs 16 +/- 8 mL/kg per min, P = NS). Echocardiographic parameters showed that the degree of mitral regurgitation was significantly decreased during BV pacing compared with no pacing (1.8 +/- 1.0 before implantation vs 1.3 +/- 0.7, P < 0.01). The radionuclide LVEF was not statistically different during no pacing, versus BV pacing at 3 months or 8 months after pacemaker implantation (24 +/- 9 vs 26 +/- 11 vs 25 +/- 10%, respectively, P = NS). Of nine patients whose QRS duration was prolonged by BV pacing, two were not hemodynamically and clinically improved at the end of follow-up. Patients not improved by BV pacing had the same degree of QRS shortening (203 +/- 39 vs 167 +/- 26 ms, P < 0.01) as patients who were clinically improved during follow-up (193 +/- 40 to 171 +/- 24 ms, P < 0.01). In multivariate analysis, ischemic heart disease (P = 0.025), absence of mitral regurgitation regression (P = 0.01), and older age (P = 0.04) predicted the absence of improvement by BV pacing. By standard noninvasive measures, intermediate-term BV pacing was associated with no objective hemodynamic improvement, though more than three fourths of the patients reported being clinically improved. A global improvement in left ventricular function by BV pacing may become apparent only over longer periods of observations. Patients with CHF unimproved by BV pacing are more likely to suffer from ischemic heart disease and less likely to have BV pacing induced regression of mitral regurgitation, regardless of changes in QRS duration.

Objectives: We sought to assess the dynamic temporal course of conduction recovery during and after radiofrequency (RF) catheter ablation of the cavotricuspid isthmus., Background: Although cavotricuspid isthmus block is accepted as the best end point of ablation for typical flutter, conduction recovery is thought to underlie many eventual recurrences. Its time course and frequency have not been determined., Methods: In a prospective group of 30 patients (26 men and 4 women, age 64 +/- 12 years) undergoing ablation of typical flutter in the cavotricuspid isthmus, the morphology of the P wave during pacing from the low lateral right atrium after achievement of complete isthmus block was identified as a reference. Regression of this morphologic P wave change was confirmed to be associated with intracardiac evidence of the recovery of cavotricuspid isthmus conduction and was observed throughout the procedure both during ablation in sinus rhythm (n = 15, group B) and just after flutter termination (n = 15, group A)., Results: Stable complete isthmus block was achieved in all patients; 29 had a terminal positivity of the paced P wave. Flutter termination resulted in stable block and terminal P wave positivity in three patients, transient terminal P wave positivity and transient block despite continuing RF at the same site in five patients and no block in the remaining seven patients. Conduction recovery identified by recovery of P wave changes was nearly as common (48%) during ablation in sinus rhythm. Multiple recoveries were noted in some patients, and 72% of all recoveries occurred within 1 min. Conduction recovery was only rarely associated with coagulum, impedance elevation or pops., Conclusions: Conduction recovery in the cavotricuspid isthmus is common during and after ablation and can be accurately, dynamically and continuously observed by monitoring the recovery of the low lateral right atrial paced P wave change.

Background: Dual-loop atrial reentrant tachycardias have not been clinically described., Methods and Results: Five patients (3 men, 2 women; mean age, 48+/-16 years) were studied 24+/-15 years after surgical closure of an ostium secundum atrial septal defect for drug-resistant atrial tachycardia. Complete tachycardia mapping was performed in the right atrium with multipolar catheters and a 3-dimensional electroanatomic mapping system (Biosense), followed by linear radiofrequency ablation of the narrowest part of each complete loop. Six tachycardias with a typical flutter morphology, a cycle length of 262+/-40 ms, and a superior f-wave axis (-77+/-11 degrees ) were mapped, 4 with a Biosense map including 106+/-32 points. Five figure-8 tachycardias had a counterclockwise loop around the tricuspid valve sharing a common anterior channel with a clockwise loop around the lateral atriotomy scar. One tachycardia was thought to have 2 counterclockwise loops around the same obstacles. Radiofrequency delivery in the cavotricuspid isthmus in each case transformed the tachycardia without any pause in a different morphology tachycardia with an inferior P-wave axis (50+/-42 degrees ) and nearly the same cycle length (272+/-39 ms) but with the periatriotomy loop alone. This arrhythmia required ablation of a second isthmus: between the lower end of the atriotomy and the inferior vena cava in 4 and the superior tricuspid annulus in 1. After a follow-up of 19+/-6 months, there were no recurrences., Conclusions: Figure-8 double-loop tachycardias mimicking the ECG pattern of a common atrial flutter occur in some patients after a surgical atriotomy. Ablation of 1 loop produces a sudden transformation to a new reentrant tachycardia formed of the remaining loop that requires ablation at a second isthmus.

Relationships between ambulatory arterial pressure and arterial distensibility as assessed by ambulatory measure of the QKD interval and echocardiographic measurement of left ventricular mass and relative wall thickness were evaluated in a population of 163 untreated hypertensive patients. The height-corrected QKD100-60 interval was significantly correlated with left ventricular mass (LVM; r = -0.29, P<.001) and with relative wall thickness (r = -0.31, P<0.001). In a multivariate analysis, LVM was significantly correlated with mean arterial pressure, pulse pressure, and age, whereas the relative wall thickness was correlated with the QKD interval and the mean arterial pressure. The concentric character of the LVH of the hypertensive patient was thus linked to the reduction in arterial distensibility.

Objectives: It has been suggested that hypertensives at high risk of cardiovascular complications can be identified on the basis of their left ventricular mass as determined echographically. However, there is as yet a lack of consensus on the mode of indexation (body surface area, height, height 2.7) of left ventricular mass (LVM), and on the cut-off values for definition of left ventricular hypertrophy (LVH). The main objective of this study is to test the influence of the different modes of indexation for LVM on the prevalence of LVH in a population of never treated hypertensive patients on the basis of cut-offs for LVM based upon its relationship with ambulatory blood pressure (BP) measurement., Methods: A population of 363 untreated hypertensives was investigated using a standardised procedure. The men and women were analysed separately. We studied the relationship between mean daytime ambulatory systolic BP and LVM and calculated the LVM cut-off for a BP of 135 mm Hg using three different methods of indexation. On the basis of these criteria, the population was divided into those with and those without LVH., Results: The prevalence of LVH was found to be higher when LVM was indexed to height2.7 (50.4%) or height (50.1%). Prevalence was lowest when LVM was indexed to body surface area (48.2%), which tended to minimise the hypertrophy in obese individuals. Only indexation by height 2.7 fully compensates for relationships between height and ventricular mass in this population., Conclusions: Indexing LVM to height 2.7 thus appeared to give a more sensitive estimate of LVH by eliminating the influence of growth. Cut-offs of 47 g/m2.7 in women and 53 g/m2.7 in men corresponded to a cardiovascular risk indicated by a daytime systolic BP >/=135 mm Hg.