Bogumiła Bacior

Left ventricular lead implantation at a phrenic stimulation site is safe and effective.

AIMS Phrenic stimulation (PS) is a major limiting factor for both left ventricular (LV) lead placement and cardiac resynchronization therapy (CRT) delivery. We have developed a protocol allowing for LV lead implantation at a PS site based on specific criteria regarding phrenic and LV acute capture thresholds. The present study examined long-term outcomes in patients treated using this protocol. METHODS AND RESULTS A total of 211 consecutive patients underwent CRT device implantation. The procedure was successful in 201 patients. Leads were implanted at a PS site in 27 patients (PS patients) and a non-PS site in 174 patients (non-PS patients). Left ventricular leads were placed at a PS site only on the following conditions: no PS at ≤3.5 V/0.5 ms, LV threshold ≤1.5 V, and a PS/LV threshold ratio >4. The mean PS threshold decreased (5.1 ± 1.6 vs. 2.8 ± 1.6 V, P < 0.001) and the mean LV threshold remained stable (1.0 ± 0.7 vs. 0.9 ± 0.8 V, P = 0.6) in PS patients over the 16 ± 9 month follow-up. Only one PS patient experienced non-reprogrammable PS and required a re-operation. Seven PS patients required very low LV channel output programming without the usual safety margin of twice the LV threshold amplitude or three times the pulse width. However, 100% LV capture was shown in those patients during daily activity. Non-reprogrammable PS occurred in 2 of the 174 non-PS patients. CONCLUSION Our strategy for LV lead implantation at a PS site was found to result in long-term safe and effective outcomes.

Effect of exercise rehabilitation on heart rate variability in hypertensives after myocardial infarction.

Objective The aim of the study was to find out whether the presence of hypertension affects heart rate variability in patients rehabilitated after myocardial infarction. Design Echocardiography, exercise testing and 24 h Holter monitoring were performed before and after 27 days of early postdischarge cardiac rehabilitation. Patients The study population consisted of 64 patients aged 34–65 years (mean ± SD 51.6 ± 6.6) discharged from hospital after a first myocardial infarction who were subdivided into two groups, group A comprising 34 patients with arterial hypertension which had lasted 4.8 ± 2.1 years and group B comprising 30 normotensives. Main outcome We expected exercise rehabilitation to affect heart rate variability, exercise tolerance and myocardial ischemia in patients after myocardial infarction with and without arterial hypertension. Results At baseline no intergroup differences were seen in the duration of exercise, workload and heart rate variability parameters. All parameters increased significantly after cardiac rehabilitation (P < 0.01): SD of all normal RR intervals 123.4 ± 30.0 versus 123.8 ± 30.0 ms; SD of the averages of normal RR intervals in all 5-min segments of the entire recording 115.1 ± 30.5 versus 116.3 ± 28.3 ms; mean of the SD of all normal RR intervals for all 5-min segments of the entire recording 49.0 ± 12.5 versus 48.3 ± 11.8 ms; square root of the mean of the sum of the squares of differences between adjacent RR intervals 29.7 ± 9.1 versus 28.0 ± 8.5 ms; percentage of differences between adjacent RR intervals > 50 ms 7.9 ± 6.0 versus 7.1 ± 6.1% (group A versus group B, respectively, NS). The duration of exercise and the workload were significantly increased (the rise was higher in normotensives). No differences were seen in the frequency and severity of silent myocardial ischemia. Conclusions Early stationary exercise rehabilitation after myocardial infarction improves heart rate variability parameters and exercise tolerance both in hypertensives and in normotensives.

Prospective evaluation of diagnostic work-up in syncope patients: results of the PL-US registry

AIMS Syncope is a common problem. Demographic and clinical characteristics of patients admitted to different types of centres may vary, physicians adherence to the guidelines has been examined only in a few studies, and the requirements for implantable loop recorders (ILR) have not been well defined. The aim of this study was to (i) compare demographic and clinical characteristics of patients with syncope diagnosed and treated in tertiary electrophysiology cardiac centres and those attending syncope units or general hospitals, (ii) assess how physicians adhere to the published guidelines, and (iii) calculate the requirement for ILR insertion. METHODS AND RESULTS In total, 669 consecutive patients with syncope, admitted to 18 electrophysiological cardiac tertiary centres over a mean of 3 months (range 1-10 months), entered a special Internet database called the PL-US (Polish patients with Unexplained Syncope) registry. Detailed demographic and clinical characteristics of the patients, including the results of all diagnostic tests performed, were analysed. Adherence to the guidelines was assessed, based on the published recommendations. The ILR implantation was indicated when (i) all other tests were inconclusive (unexplained syncope) and (ii) syncope associated with injury or presence of organic heart disease or past medical history and ECG suggesting arrhythmic syncope. Syncope of cardiac/arrhythmic origin was the most frequent diagnosis (53%), followed by reflex syncope (33%). Adherence to the guidelines was less than satisfactory-measurement of blood pressure in an upright position, carotid sinus massage, exercise testing, and electrophysiological study were underused, whereas prolonged ECG monitoring and neurological consultations were overused. Unexplained syncope had 58 (9%) patients, and 42 (72%) of them had indication for ILR which accounts for 6% of the whole study population. The calculated need for ILR was 222 implants/million inhabitants/year. CONCLUSION Patients with syncope admitted to the tertiary electrophysiology cardiac centres are a highly selected group of patients with syncope and differ in their characteristics as well as underlying diseases to those managed at general hospitals, outpatient clinics, or special syncope units. In Poland, the adherence to the published guidelines is far from satisfactory. At least 6% of all consecutive patients with syncope are candidates for ILR insertion.

Baseline tissue Doppler imaging-derived echocardiographic parameters and left ventricle reverse remodelling following cardiac resynchronization therapy introduction

Introduction The aim of the study was to assess the relation of baseline mechanical dyssynchrony with the left ventricular end-systolic volume (LVESV) decrease following cardiac resynchronization (CRT) therapy introduction. Material and methods Sixty consecutive patients (aged 66.3 ± 8.7 years; 57 men) with chronic heart failure (71.7% of ischaemic and 28.3% of non-ischaemic origin) and current indications for CRT were assessed before and 3 months after biventricular heart stimulator implantation. Longitudinal movements of twelve segments of the left ventricle (LV) (6 basal and 6 midlevel) and two segments of the right ventricle (RV) were analysed using tissue Doppler imaging (TDI) techniques with time from onset of Q wave in ECG to peak systolic velocity in colour-coded TDI (TTDI), time to peak strain (Tstrain) and time to peak strain rate (Tstrain rate). Minimal and maximal time differences within LV and between LV and RV walls were calculated. Results In the study group LVEF and 6-min walk test distance increased, while NYHA class, NT-proBNP level, left ventricular end-diastolic volume and LVESV decreased. Significant correlations between the magnitude of LVESV reduction with maximal time differences between Tstrain of 12 LV segments (r=0.34, p = 0.017) and time differences between TTDI basal LV-RV segments (r = –0.29, p=0.041) were found. Conclusions Only a few TDI-derived parameters such as maximal time differences between Tstrain of 12 LV segments and TTDI difference of LV-RV basal segments can be useful to predict the magnitude of left ventricle reverse remodelling after CRT introduction.

HIGHER PREVALENCE OF HYPERTENSION IN PATIENTS WITHOUT LEFT VENTRICLE REVERSE REMODELING FOLLOWING CARDIAC RESYNCHRONIZATION THERAPY IMPLEMENTATION: PP.1.21

Purpose: The aim of the study was to compare initial basic clinical and echocardiographic data in congestive heart failure (CHF) patients undergoing cardiac resynchronization therapy (CRT) between groups with and without left ventricle reverse remodeling (a positive long-term prognostic factor) following the therapy introduction. Methods: Sixty consecutive patients (aged 66.3 +/- 8.7; 57 men) with CHF of NYHA III-IV despite optimized pharmacotherapy, with left ventricular end-diastolic diameter (LVEDd) > 55 mm, left ventricular ejection fraction (LVEF) <35% and QRS > 130ms were assessed before and 3 months after BiV stimulation implantation. Patients developing at least 10% reduction of left ventricular end-systolic volume (LVESV) - reverse remodeling - were classified as responders to CRT, otherwise were considered as non-responders. Results: In the whole study group LVEF and 6-minute walk test (6-MWT) distance increased, left ventricular end-diastolic volume (LVEDV), LVESV and NYHA class decreased. Both groups did not differ significantly initially regarding left ventricular diameters and volumes, LVEF, 6-MWT and NYHA class as well as when considering clinical data of age, sex, weight, BMI, rates of ischaemic background of CHF, concomitant diseases, smoking or pharmacological treatment. The differences involved more common hypertension and higher permanent atrial fibrillation prevalence in non-responders (84% vs 50%, p=0.007 and 27% vs 18%, p = 0.048, respectively) and higher concentration of NT-proBNP in this group (2005 +/- 1632 pg/ml vs 3150 +/- 2034 pg/ml, p = 0.019) as compared to responders. Conclusions: Basic echocardiographic data did not predict left ventricle reverse remodeling. More common hypertension and higher permanent atrial fibrillation prevalence and NT-proBNP concentration were found in the group without at least 10% LVESV reduction in the 3-month-follow-up.

THE INFLUENCE OF CARDIAC RESYNCHRONIZATION THERAPY IN CHRONIC HEART FAILURE ON RESPIRATORY PROFILE AND AUTONOMIC MODULATION: PP.1.29

Aim: Cardiac resynchronization therapy (CRT) has been demonstrated to have a favorably impact on clinical outcome in patients with chronic heart failure (CHF). The aim of our study was to determine the effect of CRT on respiratory profile and autonomic modulation in CHF. Methods: Into our pilot analysis we included only CHF patients in NYHA class III presenting with sinus rhythm (N=8, mean age: 60.20 ± 7.85yr, mean EF 23.22 ± 6.70%). In all patients, beat-to-beat blood pressure (BP) monitoring and polysomnography were performed. Baroreflex function was assessed by the sequence technique (PI/SBP sequences). Based on polysomnography recording apnea-hypopnoea index (AHI), mean oxygen saturation, number of central, obstructive, mixed apneas and hypopnoea were calculated. Subjective sleep quality was assessed by the Pittsburg Sleep Quality Index (PSQI). All data was evaluated before CRT implantation procedure and after 3 months. Results: As compared to baseline after CRT therapy we observed a trend toward increase of BRS after the CRT therapy assessed by sequence technique (5.60 ± 0.09 vs 9.69 ± 8.22 ms/mmHg). All patients have breathing abnormalities with AHI > 5. CRT led to insignificant decrease in central apnoeas (187.66 ± 62.77 vs 74.66 ± 103.36, p = 0.1) along with a trend of increase in mixed and obstructive apnea number and hypopnoea number. No changes were noticed pertaining AHI (41.76 ± 8,6 vs 40.26 ± 21.6, NS), mean oxygen saturation (93.16 ± 1.40 vs 92.53 ± 1.58, NS) and PSQI (6.33 ± 2.08 vs 5.33 ± 1.15, NS). Conclusions: CRT therapy may lead to insignificant improvement in autonomic regulation and change in respiratory pattern shifting the balance between central and other breathing disordered events toward the latter ones. The role of this observation, its mechanism and prognostic implications deserves to be determined on a larger patients group in a prospective study.