Effects of radiofrequency catheter ablation on myocardial performance index and plasma NT-Pro-BNP levels in patients with Wolff-Parkinson-White syndrome.

BACKGROUND: The myocardial performance index (Tei index) is an echocardiographic index of combined systolic and diastolic functions. Brain natriuretic peptide (BNP) and its biologically inactive fragment N-terminal pro-BNP (NT-pro-BNP) are secreted by the heart in response to myocardial stretch. In this study, we investigated Tei index and NT-pro-BNP levels in patients with Wolff-Parkinson-White (WPW) syndrome before and after radiofrequency catheter ablation therapy (RFCA). METHODS: Thirty patients (19 males, 11 females, aged 35.5 +/- 14.4 years) with WPW syndrome were enrolled in this study. Echocardiographic examination was performed before and 24 hours after RFCA. Tei index was calculated using Doppler echocardiography. Blood samples were taken before and 24 hours after RFCA to detect levels of NT-pro-BNP. RESULTS: Although isovolumic contraction time (IVCT) and isovolumic relaxation time (IVRT) did not change, aortic ejection time (ET) was decreased after RFCA (276 +/- 22 ms vs 254 +/- 30 ms, P < 0.01). So Tei index was significantly higher in postablation period (0.36 +/- 0.11 vs 0.42 +/- 0.21, P < 0.05). NT-pro-BNP levels did not change significantly after RFCA. CONCLUSIONS: We demonstrated that restoration of normal atrioventricular conduction by RFCA, leads to increase in Tei index but does not effect plasma NT-pro-BNP levels.

Effect of cardiac resynchronization therapy on mean platelet volume.

OBJECTIVE: Cardiac resynchronization therapy (CRT) increases cardiac performance and decreases morbidity and mortality in patients with heart failure. Mean platelet volume (MPV), a marker of platelet hyperreactivity, was found to be increased in both chronic heart failure and thromboembolic events. Systemic and pulmonary thromboembolism is a frequent complication of heart failure.The aim of this study is to determine the effects of cardiac resynchronization therapy on MPV values. METHODS AND RESULTS: Fifty-six heart failure patients with increased QRS duration underwent biventricular pacemaker implantation. Blood samples were collected the morning before implantation and at six months follow-up. Response criteria were: an increase in ejection fraction of more than 10% from baseline at six months or no hospitalization for major cardiac events during the first six months.The mean MPV values were decreased from 9.3 +/- 0.5 fl to 8.3 +/- 0.5 fl. Patients with recorded major cardiac events in the follow-up period had no statistically significant decrease in MPV values. CONCLUSIONS: In our study we found that cardiac resynchronization therapy leads to a decreased MPV and clinical improvement in patients with heart failure that is accompanied with a decrease in MPV.

Effect of radiofrequency catheter ablation on Doppler echocardiographic parameters in patients with Wolff-Parkinson-White syndrome.

The aim of this study was to compare the conventional Doppler echocardiographic parameters before and after accessory pathway ablation in patients with Wolff-Parkinson-White (WPW) syndrome. Thirty patients (19 males, 11 females) aged 35.5 +/- 14.4 years were enrolled in the study. All patients underwent successful radiofrequency catheter ablation (RFCA). Echocardiograhic examination was performed before and after RFCA. Aortic and pulmonary flows, diastolic early (E) and late (A) transmitral filling velocities, their velocity time integrals (VTI), mitral diastolic filling time (DFT), deceleration time (DT), isovolumic relaxation time (IVRT), aortic ejection time, and aortic VTI were assessed before and after RFCA. We found that the pulmonary valve opened earlier than the aortic valve when the accessory pathway was located on the right ventricular side (P = 0.02). Otherwise, if the accessory pathway was located on the left ventricular side, the aortic valve opened earlier (P < 0.01). Intervals between the onsets of aortic and pulmonary flows were shortened after RFCA (P = 0.01). We also observed prolongation of DFT (P < 0.001), increases in A velocity (P < 0.05) and its VTI (P < 0.01), as well as a decrease in the E/A ratio (P < 0.01) and shortening of aortic ejection time (P = 0.01) with restoration of AV conduction. We conclude that Doppler echocardiographic examination can provide clues about accessory pathway location and RFCA causes some significant changes in Doppler echocardiographic time intervals. These changes confirm that cardiac synchrony is restored after RFCA.

An electrocardiographic algorithm for determining the location of pacemaker electrode in patients with right bundle branch block configuration during permanent ventricular pacing.

The expected morphology of right ventricular pacing is a left bundle branch block (LBBB) pattern. However, right bundle branch block (RBBB) can also be seen during permanent right ventricular pacing. The aim of this study was to develop an electrocardiographic algorithm to differentiate this benign condition from septal and free wall perforation with subsequent left ventricular pacing. Three hundred consecutive patients who had permanent ventricular or dual-chamber pacemaker implantation between 1999 and 2000 were screened and 25 patients (8.3%) who exhibited RBBB configuration were included in the study. Echocardiograms and chest radiographs were evaluated in order to identify the pacing lead location in this group. The authors formed a study group with their own 25 patients and 22 cases of RBBB with permanent pacemaker from previous publications (total 47 patients). Frontal axis, QRS morphology in lead V(1), and the precordial transition point, which is defined as the precordial lead where R wave amplitude is equal to S wave amplitude, were examined. Placement of precordial leads V(1) and V(2) 1 interspace lower than the standard location (Klein maneuver) eliminated the RBBB pattern in 12 patients. RBBB pattern with "true right ventricular pacing" was detected in 24 of the 25 patients, and in 11 of the 22 patients reported in the literature (total 35 patients). Right ventricular pacing was correctly identified in 34 of 35 patients with use of criteria including left superior axis deviation, RS or qR morphology in lead V(1), and precordial transition at lead V(3) with a high sensitivity and specificity. A simple surface electrocardiogram can accurately predict the lead location in patients having RBBB morphology with right ventricular pacing.

Long-term effects of cardiac resynchronization therapy on heart rate and heart rate variability.

Congestive heart failure is characterized by significant autonomic dysfunction. Development of left bundle branch block in congestive heart failure is a predictor of worse outcome. There are several lines of evidence that cardiac resynchronization therapy (CRT), by biventricular stimulation in patients with severe heart failure and left bundle branch block, improves autonomic functions which can be quantified by measuring heart rate variability. The aim of the present study was to assess the effect of CRT on autonomic functions quantified by heart rate variability and mean heart rate (HR) in patients with advanced heart failure and left bundle branch block in short and long-term follow-up. A total of 35 patients with systolic heart failure and left bundle branch block (mean-age 60 +/- 11 years; 24 male and 11 female; mean left ventricular ejection fraction [EF]: 22.3 +/- 3%) were enrolled. Clinical assessment and echocardiographic examination were performed at baseline and every three months. Continuous electrocardiographic monitorization by 24-hour Holter recordings was performed pre-implantation, 3 months and 2 years after implantation. Mean HR and one of the time-domain parameters of heart rate variability, standard deviation of the R-R intervals (SDNN) were measured. CRT was associated with a decrease in the mean duration of QRS, and an increase in diastolic filling time, the rate with which the left ventricular pressure rises (dP/dt), and left ventricular ejection fraction. Decrease in mean heart rate and increase in SDNN were statistically significant in the third month and second year recordings when compared to baseline recording (p values were < 0.001 for both). In conclusion, CRT with biventricular pacing provides sustained improvement in autonomic function in patients with advanced heart failure and left bundle branch block.

Late perforation of the heart, pericardium, and diaphragm by an active-fixation ventricular lead.

This case report describes a late perforation of right heart wall, pericardium, and diaphragm by an active-fixation ventricular lead without development of pericardial effusion and cardiac tamponade even under oral warfarin treatment.

Sequential evaluation of left ventricular systolic and diastolic function after radiofrequency catheter ablation.

Radiofrequency (RF) catheter ablation has become standard therapy for many types of arrhythmias. RF energy may cause deterioration in left ventricular function by damaging the myocardium. The aim of the present study was to assess the changes in left ventricular function after catheter ablation using various echocardiographic parameters. Forty patients (22 women), aged 37 +/- 14 years (range, 15-76 years), underwent catheter ablation for various tachycardias. Routine echocardiogaphic examination was done in all patients. Left ventricular systolic function was evaluated by the modified Simpson method and tissue Doppler. With regard to left ventricular diastolic function parameters, diastolic early (E) and late (A) transmitral filling velocities, deceleration time (DT), isovolumetric relaxation time (IVRT), and tissue Doppler parameters were assessed. All ventricular function parameters were assessed before, and 1 hour, 1 day, and 1 month after the catheter ablation procedure. To avoid any influence of heart rate on diastolic function parameters, the E/A ratio, DT, and IVRT were adjusted to heart rate (cE/A, cDT, cIVRT). No changes in left ventricular systolic function after the ablation were observed. After the ablation procedure (1 hour, 1 day, and 1 month) the cE/A ratio decreased from 1.42 +/- 0.43 to 1.19 +/- 0.40, 1.18 +/- 0.40, and 1.30 +/- 0.33 (P = 0.009), respectively. cDT increased from 210 +/- 54 to 272 +/- 64, 255 +/- 60, 240 +/- 64 (P = 0.001), respectively. Likewise cIVRT increased from 113 +/- 22 to 133 +/- 54, 123 +/- 27, 117 +/- 19 (P = 0.007), respectively. Significant changes were also observed concerning tissue Doppler parameters in assessing diastolic function. Although no significant changes were observed in systolic function after RF ablation, this procedure may have some detrimental effects on ventricular diastolic function para-meters.

An unusual cause of reflex cardiovascular syncope: vagal paraganglioma.

Vagal paraganglioma is one of the rare tumors of the neuroendocrine system. We are reporting a vagal paraganglioma case presented with uncommon features of the disease: asystole and syncope. Syncope episodes occurred 3 years before the major symptoms of the disease. Dual chamber pacemaker failed to prevent syncope attacks because of the vasodepressor component. The patient was treated successfully with en bloc removal of tumor and vagal nerve. Syncope episodes disappeared after operation.

Inhibition of biventricular pacing by far-field left atrial activity sensing: case report.

This case report describes a patient with biventricular pacemaker in whom a far-field sensing of left atrial activity by the pacemaker's ventricular channel resulted in ventricular pacing inhibition. Placing of the left ventricular pacing electrode in the proximal part of the coronary sinus tributary resulted in this far-field sensing problem, which was resolved following decreasing the ventricular sensitivity. The authors suggest that the far-field sensing of the left atrial activity should be kept in mind for troubleshooting of an atrio-biventricular pacing system.

Pacemaker related endocarditis: analysis of seven cases.

Vegetative electrode infection following permanent pacemaker implantation is a rare and serious complication. Among 1920 patients who underwent permanent pacemaker implantation in our institute between 1980 and 2000, 7 patients aged 65 to 78 years were diagnosed to have pacemaker related endocarditis. In this study, the clinical course and management strategies for these patients are reviewed. The most frequently encountered factors contributing to development of pacemaker infection were local complications such as postoperative hematoma and inflammation, and recurrent surgical interventions on the pacemaker system. In blood cultures S. aureus was the most common causative microorganism. Echocardiography could be performed in 5 patients. Three patients were referred to open-heart surgery for total removal of the pacemaker system, and one patient had his pacemaker system removed percutaneously. The remaining 3 patients did not agree to either surgical or percutaneous removal. These patients have been under antibiotic therapy for approximately 3 years and they still do not have any signs of a serious infection. Consequently, in patients with permanent pacemakers, infective endocarditis should be considered in the presence of fever and local symptoms. Blood cultures should be obtained and echocardiography should be performed. Complete removal of the pacemaker system with intensive antibiotic treatment is necessary for complete eradication of the infection. However, if percutaneous or surgical removal of the electrodes cannot be done because of high perioperative risk or the patient does not agree to undergo either method, medical treatment with long term antibiotic use may be considered as an alternative.

Left circumflex coronary artery bridging.

Myocardial bridging most frequently occurs on the left anterior descending coronary artery and may cause ischemia and related complications. Right coronary artery myocardial bridges (MB) are rare. We report a patient with an unusual coronary bridge, a left circumflex coronary artery bridge, who presented with exercise-induced angina pectoris that was relieved with medical therapy.

Differentiation of narrow QRS complex tachycardia types using the 12-lead electrocardiogram.

BACKGROUND: Previous studies have shown that only 80% of narrow QRS supraventricular tachycardia (SVT) types can be differentiated by standard 12-lead electrocardiographic (ECG) criteria. This study was designed to determine the value of some new ECG criteria in differentiating narrow QRS SVT. METHODS AND RESULTS: 120 ECGs demonstrating paroxysmal narrow QRS complex tachycardia (QRS < or = 0.11 ms and rate > 120 beats/min) were analyzed. Forty atrioventricular reciprocating tachycardia (AVRT), 70 atrioventricular nodal reentrant tachycardia (AVNRT), and 10 atrial tachycardia defined with electrophysiologic study (EPS) consisted the study group. Eight surface ECG criteria were found to be significantly different between tachycardia types by univariate analysis. P waves separate from the QRS complex were observed more frequently in AVRT (70%) and atrial tachycardia (80%). Pseudo r' deflection in lead V(1), pseudo S wave in inferior leads, and cycle length alternans were more common in AVNRT (55, 20, and 6%, respectively). QRS alternans was also present during AVRT (28%). ST-segment depression (> or = 2 mm) or T-wave inversion, or both, were present more often in AVRT (60%) than in AVNRT (27%). During sinus rhythm, manifest preexcitation was observed more often in patients with AVRT (42%). When a P wave was present, RP/PR interval ratio > 1 was more common in atrial tachycardia (90%). By multivariate analysis, presence of a P wave separate from the QRS complex, pseudo r' deflection in lead V(1), QRS alternans, preexcitation during sinus rhythm, ST-segment depression > 2 mm or T-wave inversion, or both, were independent predictors of tachycardia type. CONCLUSIONS: Several new ECG criteria may be useful in differentiation of SVT types. Prediction of mechanism prior to EPS may provide additional benefits concerning the fluoroscopic exposure time and cardiac catheterization procedure.

Noncompaction of ventricular myocardium, complete atrioventricular block and minor congenital heart abnormalities: case report of an unusual coexistence.

Ventricular noncompaction is a rare cardiomyopathy characterized by numerous, prominent ventricular trabeculations and deep intertrabecular recesses and is caused by a disorder of endomyocardial morphogenesis. It can occur in patients with other congenital anomalies, such as various ventricular obstructive lesions, or in isolated form in the absence of associated anomalies. Patients with this unique disease may present with heart failure, systemic emboli, and ventricular arrhythmias. In this case report, we present an unusual coexistence of ventricular noncompaction and atrial septal aneurysm and mitral valve cleft in a young patient who presented with complete AV-block.

Prognostic implication of myocardial texture analysis in idiopathic dilated cardiomyopathy.

BACKGROUND AND AIM: Abnormal myocardial acoustic properties have been reported in patients with idiopathic dilated cardiomyopathy (IDC). The aim of this study was to investigate the relationship between quantitative ultrasonic textural alterations of myocardium and clinical outcome in IDC. METHODS: Baseline clinical and echocardiographic variables were obtained from 28 patients with IDC. By using a videodensitometric approach, quantitative myocardial texture analysis was performed on images obtained from septum and posterior wall (PW). Cyclic variation (CV) index of mean gray level (MGL) was calculated according to the formula: (MGLdiast-MGLsyst)/MGLdiastx100. All patients were followed for an average of 11+/-5 months for the occurrence of cardiac death or repeated hospitalization due to worsening of heart failure. RESULTS: During follow-up, 10 patients experienced cardiac events (6 cardiac deaths and 4 heart failure events). The CV indexes of both septum and PW were significantly lower in patients with cardiac events than those of event free patients (6.8+/-9.6% vs. 13.6+/-8.2%, P<0.05 and 5.3+/-6.4% vs.15.7+/-7.2% P<0.001, respectively). Univariate analysis defined the following variables as predictors of outcome: PW-CV index (chi2=13.0, P=0.0003), transmitral E/A ratio (chi2=12.5, P=0.0004), symptom status (chi2=8.7, P=0.003), and septum-CV index (chi2=4.7, P=0.03). Multivariate stepwise regression analysis showed that the PW-CV index (chi2=7.5, P=0.006) and E/A ratio (chi2=6.5, P=0.01) were the independent predictors of outcome. The event-free survival rate of patients with PW-CV index <11% was significantly lower than those with an index > or = 11 (35.7% vs. 92.8%, P=0,001). CONCLUSION: The assessment of severely depressed CV index provides valuable prognostic information in patients with IDC.

Echocardiographic prediction of long-term response to biventricular pacemaker in severe heart failure.

BACKGROUND: Biventricular pacing substantially improves LV systolic function and symptom status in some patients with dilated cardiomyopathy. AIMS: To assess whether the long-term benefit could be predicted from the echocardiographic parameters. METHODS AND RESULTS: Sixteen patients with dilated cardiomyopathy who underwent atrio-biventricular pacemaker implantation were analyzed in two groups: the responders (n=11) were those with a symptomatic improvement of one or more NYHA functional class; the non-responders (n=5) failed to improve at follow-up (7.6+/-5 months). Echocardiography was performed at baseline, the day after the implantation and then every 3 months. Besides the conventional parameters, the following variables were included: LV diastolic filling time (DFT); the duration of mitral regurgitation (dMR); and LV dP/dt obtained from the continuous wave mitral regurgitation curve. While the baseline DFT and dP/dt were not significantly different between non-responders and responders (256+/-105 vs. 358+/-115, P=0.14 and 564+/-199 vs. 468+/-117, P=0.44, respectively), the QRS width (149+/-15 vs. 175+/-24 ms, P=0.05) and the dMR (343+/-70 vs. 443+/-49 ms, P=0.007) were higher in the responders. The changes of dMR, DFT and QRS width by pacing were not significantly different between groups (P=0.18, 0.30 and 0.77, respectively). However, the change of LV dP/dt by pacing in the responders was significantly different than for non-responders (from 468+/-117 to 676+/-216 mmHg/s vs. from 564+/-199 to 483+/-94, P=0.002). An acute increase in LV dP/dt over 22% by pacing yielded only two false negatives and no false positives in predicting the long-term responsiveness. CONCLUSION: Patients with longer QRS and dMR are more likely to benefit from atrio-biventricular stimulation. The acute changes of Doppler derived LV dP/dt may provide valuable information in predicting the long-term response to biventricular pacing.

Long-term follow-up of pacemakers with an Autocapture pacing system.

UNLABELLED: The aim of this study was to evaluate the safety and performance of the Autocapture pacing system during a 5-year follow-up period. The study was conducted retrospectively between May 1996 and May 2001. Sixty consecutive patients who had undergone VVI pacemaker implantation using an Autocapture program with leads 1402T (n: 31) and 1452T (n: 29) were included in the study. Intraoperative measurements including a ventricular stimulation threshold test, sensing of intrinsic R wave (mV), and lead impedance (W) were done by a standard pacing system analyzer. Evoked responses (ER, mV) and polarization signals (PS, mV) were measured after the pocket was closed. Pacing thresholds by Autocapture (AC thrd, V) and Vario (Vario thrd, V), battery current (mA), and battery impedance (kW) were also repeated during predischarge and 1, 6, 12, 18, 24, 30, 40, 50, and 60 months after discharge. According to the ER and PS values an Autocapture algorithm could be activated in 49 patients (88%). The Autocapture algorithm remained active during the follow-up in all of these patients. In patients with inappropriate ER and PS values (11 patients, 12%), pacemakers were programmed to a VVIR pacing mode and Autocapture algorithm was inactivated. ER and PS values did not reach appropriate values to activate the Autocapture algorithm in any of these patients in consecutive follow-ups. Twenty-four-hour Holter monitoring could be conducted in 32 patients (53%). In all recordings, when the loss of capture occurred, it was confirmed that back-up pacing continued. When the first measurements recorded during implantation were compared to approximately the 5th year measurements; ER (9.2 mV vs 9.6 mV), PS signal (1.13 +/- 0.30 mV vs 1.15 +/- 0.72 mV), AC thrd (0.4 V vs 1.2 V), Vario thrd (0.7 V vs 1.3 V), and lead impedance (502 ohm vs 620 ohm) were not changed significantly. Battery impedance increased 1 kOhm between 30-40 months of the implantation. Seven deaths occurred during follow-up. Three patients had fatal myocardial infarction, one died due to a non-cardiac event, and the remaining three died due to progressive heart failure. CONCLUSION: ER, R wave amplitude, and PS, which are the main parameters for the continuation of Autocapture function, did not change significantly during long-term follow-up. High output back up pacing provided additional safety for sudden rises in threshold. The Autocapture pacing algorithm was found to be effective and reliable during long-term follow-up.