Pacing In Patients Research Articles

Arterial pressure changes monitoring with a new precordial noninvasive sensor

BackgroundRecently, a cutaneous force-frequency relation recording system based on first heart sound amplitude vibrations has been validated. A further application is the assessment of Second Heart Sound (S2) amplitude variations at increasing heart rates. The aim of this study was to assess the relationship between second heart sound amplitude variations at increasing heart rates and hemodynamic changes.MethodsThe transcutaneous force sensor was positioned in the precordial region in 146 consecutive patients referred for exercise (n = 99), dipyridamole (n = 41), or pacing stress (n = 6). The curve of S2 peak amplitude variation as a function of heart rate was computed as the increment with respect to the resting value.ResultsA consistent S2 signal was obtained in all patients. Baseline S2 was 7.2 ± 3.3 mg, increasing to 12.7 ± 7.7 mg at peak stress. S2 percentage increase was + 133 ± 104% in the 99 exercise, + 2 ± 22% in the 41 dipyridamole, and + 31 ± 27% in the 6 pacing patients (p < 0.05). Significant determinants of S2 amplitude were blood pressure, heart rate, and cardiac index with best correlation (R = .57) for mean pressure.ConclusionS2 recording quantitatively documents systemic pressure changes.

Evaluation of left ventricular function: does the imaging technique matter?

Measurement of left ventricular ejection fraction is a common procedure in cardiology. This is not without reason. Left ventricular ejection fraction has proven to be an important predictor of mortality in patients with heart failure and after myocardial infarction [1, 2]. It is also frequently used to monitor left ventricular remodelling after myocardial infarction and to select patients for ICD therapy and biventricular pacing [3, 4]. Next to this, measurement of left ventricular ejection fraction is used to detect cardiac toxicity in cancer treatment, especially chemotherapy with anthracyclines and related compounds (doxorubicin, daunorubicin, idarubicin, epirubicin, anthraquinone mitoxantrone) and trastuzumab [5, 6]. Therefore determination of left ventricular ejection fraction has to be correct and reproducible. Fortunately, several techniques are available to measure left ventricular ejection fraction: echocardiography, nuclear imaging, magnetic resonance imaging, CT of the heart and contrast angiography. Echocardiography is the most commonly used technique, particularly because it is a cheap and easy to perform technique, gives no irradiation gives no patient discomfort and can be used anywhere. In addition, the technique can be used in settings where MRI cannot be used and in patient with irregular heart rhythm, which makes radionuclide angiography inaccurate. Unfortunately the technique is highly operator dependent and patient dependent. Left ventricular function is frequently measured with 2D techniques with extrapolation to a 3D structure, assuming, that the four chamber view and two chamber view give a correct display of this 3D structure. In this setting, visual assessment may not always be accurate [7, 8]. Intra observer and inter observer variability improves if quantitative assessment with the Simpson’s rule is used. In some patients echocardiography is technically cumbersome (Patients with pulmonary disease, women with large breasts and patients with deformations of the thorax). Contrast enhancement can improve estimates of left ventricular ejection fraction significantly in this setting [9]. Magnetic resonance imaging gives also no radiation exposure, but is more difficult to perform and more expensive. Because of the high resolution of the images, the high endocardial intrinsic contrast, the absence of foreshortening, the absence of user-dependence, the high reproducibility, the ability to perform 3D images and the moderate to high temporal resolution, MRI has become the gold standard for the last two decades [10]. Nuclear imaging, CT of the heart and contrast angiography give radiation exposure, and are therefore contraindicated in pregnant women, are relative expensive and require contrast agents (CT and contrast angiography) with possible adverse effects. Radionuclide ventriculography was introduced three decades ago and soon became an accepted technique for measurement of left ventricular ejection fraction. This L. H. B. Baur (&) Department of Cardiology, Atrium Medical Centre Parkstad and University of Maastricht, Henri Dunantstreet 5, 6401CX Heerlen, The Netherlands e-mail: l.baur@atriummc.nl

Predictors of improved quality of life 1 year after pacemaker implantation

Patient's health-related quality of life (HRQoL) of pacemaker (PM) patients has increasingly become an important issue of health care evaluation. Currently, knowledge of pacing performance and technology is more or less outlined. However, determinants of poor or good HRQoL of paced patients require further elucidation. The purpose of this study is to determine the HRQoL 1 year after PM implantation and predictors of differences in HRQoL between pre- and post-PM implantation. We quantified the mean differences between HRQoL before implantation (baseline) and 1 year later, assessed with the generic Medical Outcomes Survey 36-Item Short-Form Survey and EuroQol (EQ5D), and the PM patient-specific AQUAREL (Assessment of QUality of life And RElated events) questionnaires, in 501 consecutively included patients in the Dutch multicenter longitudinal FOLLOWPACE cohort study. Multivariable linear regression modeling was then performed to determine predictive factors of the HRQoL 1 year after implantation. The HRQoL of the patients increased markedly in the first year after implantation. Seventy percent of the patients considered their health improved, whereas 11% experienced a complete recovery in HRQoL. The most important predictors for improved HRQoL after 1 year were HRQoL at baseline, age, presence of cardiac comorbidities, and atrial fibrillation with slow ventricular response as indication for chronic pacing. In most patients receiving a PM, HRQoL increased in the first year after PM implantation. Knowledge of the predictors of this increase may aid physicians to timely differentiate between patients who most likely will benefit most from PM implantation in terms of HRQoL.

Blood pressure drop and symptoms during ATP-test under pacing

We studied systolic blood pressure (SBP) behavior and symptoms during ATP-test in temporary paced patients. SBP drop during ATP-test is only partially prevented by pacing. During DDD paced ATP-test, SBP minimum was lower in symptomatic patients. Considering the role of endogenous adenosine in neurally-mediated syncope (NMS), our results are concurrent with a SBP fall resulting in NMS recurrence under permanent pacing.

Pacemaker therapy for the sick sinus node syndrome. Does the atrially involved pacemaker system lower the frequency of atrial fibrillation and thromboembolic complications as well as mortality?

Between 1986 and 1992, pacemakers were implanted in 307 patients with symptoms caused by the sick sinus syndrome (SSS). 301 patients were regularly followed up (161 men, 146 women, mean age 72.9 [27-91] years) of whom 180 had a VVI, 65 and AAI and 58 a DDD/DDI pacemaker. Mean follow-up period was 58.3 months for VVI-stimulated patients and 35.6 months for atrial paced patients. The data were analysed retrospectively to ascertain whether a change in pacemaker treatment to a more physiological system produced any lowering in the mortality rate, incidence of permanent atrial fibrillation (AF), and thromboembolic phenomena. The annual mortality rate of the VVI-stimulated patients was 6.9%, that of atrial paced patients 2.8%. Age, abnormal ventricular function, survived resuscitation and diabetes mellitus each correlated with a shortened life expectancy already at the time of implantation, regardless of the pacemaker mode. Permanent AF was more frequent during VVI stimulation (16% vs 7%), especially if it had been preceded by intermittent AF (26% vs 13%). But there was no significant difference with regard to transitory cerebral ischaemic episodes and peripheral arterial emboli (15% vs 10%). Fewer patients with atrial pacing went into heart failure (20% vs 30%). Four patients developed a high-grade atrioventricular (a-v) block on AAI stimulation (annual incidence 2.4%). - These observations suggest that patients with SSS should always have atrial paced pacemaker systems. If a-v conduction is disturbed, a bifocal pacemaker is the system of choice.

Rate Responsive Pacemakers: A Rapid Assessment Protocol

Rate responsive (RR) pacemakers are commonly implanted with nominal conservative factory-set responsiveness, which is usually accepted because established exercise protocols are time-consuming. We aimed for efficient assessment of RR pacemaker settings. We tested exercise heart rates in controls and paced patients using a brief exercise test that approximates real-life levels of exertion. The test used a nonmotorized treadmill: 30 seconds walking at patient-determined speed followed by 15 seconds brisk exertion. Subjects totaled 110: 26 with RR pacemakers; 22 with non-RR pacers; 27 "sick" nonpaced control patients; and 35 healthy controls. Heart rate (HR) was measured prior to exercise, after 30 seconds of casual walk, after 15 seconds of brisk walk, and 1 minute into recovery. Testing required <5 minutes from set-up to recovery. The 26 RR pacer patients had a mean HR at rest = 74 +/- 10 beats per minute (bpm), walk = 87 +/- 14, and brisk = 94 +/- 18 (increase 27%). Non-RR pacer patients (n = 22): rest = 73 +/- 12 bpm, walk = 88 +/- 14, and brisk = 94 +/- 17 (increase 24.3%, P = 0.60 vs RR patients). "Sick" controls (n = 27): rest = 78 +/- 14 bpm, walk = 102 +/- 17, and brisk = 117 +/- 18 (increase 51.9%, P< 0.001 vs RR pts). For the healthy controls, HRs were at rest 83+/11 bpm, walk = 104 +/- 12, and brisk = 117 +/- 13 (P< 0.001 compared to both paced groups; P = NS vs sick controls). Nominal RR settings may be suboptimal for many patients. The nonmotorized treadmill test allows quick and inexpensive assessment of RR programming, with the potential for efficient RR optimization.

Clinical application of pacemakers in atrial tachyarrhythmias

The diagnostic programmes of modern pacemakers have increased our knowledge of atrial tachyarrhythmias (ATAs) in chronically paced patients. These programmes also support the evaluation of the effects of pharmacological treatment of ATAs. The success of interruption and/or prevention of ATAs with pacemakers depends strongly on the diagnostic accuracy and the properties of the pacing algorithms, their individual programming and the site and configuration of the pacing leads. Atrial septum pacing can be beneficial in patients with paroxysmal atrial fibrillation and prolonged P wave duration. Recent large-scale studies on preventive and interruptive atrial pacing of ATAs show modestly positive or no results. Therefore, atrial pacing therapy for ATAs should be considered cautiously, serving as an adjuvant to pharmacological treatment rather than as a primary intervention. This also applies for pacing interventions for ATAs in cardiac resynchronisation therapy. The pacemaker algorithms for the detection of ATAs and atrial lead configuration are crucial for the success of pacemaker-mediated prevention or interruption of ATAs. The success of these interventions is dependant on future improvements of pacemaker technology. (Neth Heart J 2008;16(Suppl1):S20-S24.).

Upgrading to biventricular pacing/defibrillation systems in right ventricular paced congestive heart failure patients: prospective assessment of procedural parameters and response rate

Cardiac resynchronization therapy (CRT) is indicated in patients with heart failure and bundle branch block. It is less clear whether this includes patients with pre-existing right ventricular pacemaker/defibrillator systems, particularly with respect to implantation success and clinical benefit. In consecutive patients scheduled for CRT, we prospectively compared implantation success, procedural parameters, and clinical response in 'de novo' vs. upgrade procedures of previously implanted right ventricular systems. CRT implantation was attempted in 79 consecutive patients (64 +/- 11 years, 63 male, 38 ischaemic, 41 non-ischaemic cardiomyopathy). De novo implantation was performed in 61 patients, upgrade procedures in 18 patients. Implant success (92 vs. 94%, P = 1.00), procedure duration (153 +/- 43 vs. 164 +/- 65 min, P = 0.51), fluoroscopy time (25 +/- 18 vs. 32 +/- 22 min, P = 0.18) or dose (40 +/- 31 vs. 52 +/- 49 Gy/cm(2), P = 0.35), and response rate (66 vs. 59%, P = 0.5) were comparable for both groups. Procedural aspects, implantation success, and clinical response to CRT were comparable for patients undergoing de-novo vs. upgrade procedures. Accordingly, patient selection for upgrading should be the same as for new CRT implantation.

Ethnocultural Variations in Mental Illness Discourse: Some Implications for Building Therapeutic Alliances

Ethnocultural Variations in Mental Illness Discourse: Some Implications for Building Therapeutic Alliances

Bifocal versus unifocal right atrial pacing under plasma level controlled sotalol to prevent atrial fibrillation in patients with symptomatic sinus bradycardia and paroxysmal atrial fibrillation

Bifocal right atrial pacing (BP) has been reported to increase arrhythmia-free intervals in patients with paroxysmal atrial fibrillation (PAF) under antiarrhythmic drugs. This study compares AF burden with unifocal pacing (UP) vs BP under sotalol. In 19 patients with PAF a DDDR pacemaker with right atrial lateral and CS ostial leads was implanted. Sotalol was initiated. After a 3 month back-up pacing period patients were randomized to continuous UP or BP for 3 months and crossed over for 3 more months. Primary endpoint was AF burden. Secondary endpoints included number of episodes, time to first recurrence and safety of BP. The intention to treat analysis revealed 12.4% AF during back-up, 6.2% during UP and BP (p=0.91 UP vs BP, p=0.08 back-up vs UP and p=0.07 back-up vs BP). Per protocol analysis showed no advantage of either pacing mode (UP 4.8% and BP 5.4% AF, p=0.64). Overdrive pacing reduced AF burden to 6.2 vs 8.8% during back-up (p=0.09). Septal lead dislodgement occurred in 3 patients. Atrial pacing tends to reduce AF burden in patients with PAF under sotalol. An incremental effect of BP vs UP cannot be confirmed. BP may be complicated by elevated lead dislodgement rates.

Accelerometer‐Derived Time Intervals during Various Pacing Modes in Patients with Biventricular Pacemakers: Comparison with Normals

Changes due to biventricular pacing have been documented by shortening of QRS duration and echocardiography. Compared to normal ventricular activation, the presence of left bundle branch block (LBBB) results in a significant change in cardiac cycle time intervals. Some of these have been used to quantify the underlying cardiac dyssynchrony, assess the effects of biventricular pacing, and guide programming of ventricular pacing devices. This study evaluates a simple noninvasive method using accelerometers attached to the skin to measure cardiac time intervals in biventricularly paced patients. Ten patients with biventricular pacemakers previously implanted for congestive heart failure were paced in the AAI mode, then in atrioventricular (AV) sequential mode from the right and left ventricles followed by biventricular pacing. Simultaneous recordings were obtained by 2D, Doppler echocardiography as well as by accelerometers. Similar recordings were obtained from 10 gender, aged matched, normal controls during sinus rhythm. Compared to normals, heart failure patients paced in AAI mode had prolonged isovolumetric contraction time (IVCT), shorter ventricular ejection time (LVET), and prolonged isovolumetric relaxation (IVRT). With biventricular pacing the IVCT decreased, but the LVET and IVRT did not change significantly. There was excellent correlation between the echo and accelerometer-measured intervals. Shortening of the IVCT measured by an accelerometer is a consistent time interval change due to biventricular pacing that probably reflects more rapid acceleration of left ventricular ejection. The accelerometer may be useful to assess immediate efficacy of biventricular pacing during device implantation and optimize programmable time intervals such as AV and interventricular (VV) delays.

Preserved Left Ventricular Ejection Fraction Following Atrioventricular Junction Ablation and Pacing for Atrial Fibrillation

Right ventricular apical (RVA) pacing creates ventricular dyssynchrony and may compromise left ventricular ejection fraction (LVEF). The impact of RVA pacing in patients who have undergone atrioventricular junction (AVJ) ablation for atrial fibrillation (AF) is unclear. We sought to determine whether RVA pacing after AVJ ablation for patients with AF compromises LVEF in the short- or long-term. We studied 286 patients with AF who underwent AVJ ablation and RVA pacing at our institution between 1990 and 2002. Patients were stratified into a short-term follow-up group (LVEF reassessed by echocardiography within a year after AVJ ablation, n = 134) and a long-term group (LVEF reassessed after a year, n = 152). Among all 286 patients (mean follow-up 20 months), we observed no change in mean LVEF after AVJ ablation and RVA pacing (48% before vs. 48% after, P = 0.42). Short-term follow-up patients had a statistically significant improvement in mean LVEF (46% before vs. 49% after, P = 0.03), whereas there was no statistically significant change in mean LVEF in long-term follow-up patients (49% before vs. 48% after, P = 0.37). Only 9% of short-term patients, 15% of long-term patients, and 1% of patients with baseline LVEF <or= 40% experienced >or=10% absolute decrease in LVEF. Baseline LVEF > 40% was a multivariate predictor of LVEF decline. RVA pacing after AVJ ablation does not compromise LVEF in the short- or long-term for the vast majority of patients. Better predictors are needed to help us select patients for biventricular pacing after AVJ ablation.

Abstract 1604: Response to Cardiac Resynchronization Therapy Differs Between Patients With and Without Previous Right Ventricular Pacing

Background: Previous large studies on the effects of cardiac resynchronization therapy (CRT) in patients with heart failure have generally excluded patients previously paced from the right ventricle (RV). Previously RV paced patients (RVp) can exhibit an iatrogenic cause of dyssynchrony and reduced systolic function and thus, may respond differently to CRT than patients not previously RV paced (nRVp). The purpose of this study was to test the hypothesis that RVp patients have greater improvements in left ventricular systolic function, volumes, and dyssynchrony in response to CRT than nRVp. Methods: Standard echocardiograms with tissue Doppler imaging were performed before and after chronic CRT in RVp (n = 21, 16 male) and nRVp (n = 70, 54 male) heart failure patients. Ejection fraction (EF), left ventricular end diastolic (LVEDV) and systolic (LVESV) volumes were calculated using the biplane Simpson’s method. Longitudinal dyssynchrony was calculated as the standard deviation of time to peak displacement (TT-12) of 12 segments in the apical views. Using mid-ventricular short axis views and speckle-tracking methods, radial dyssynchrony (Rad dys ) was calculated as the maximal time difference between six myocardial segments for peak radial strain. Echo response was defined as ≥ 15% reduction in LVESV. Results are reported as mean ± SD. Results: Significant baseline differences (p &lt; 0.05) were observed between groups (RVp vs. nRVp) for age (74 ± 13 vs. 67 ± 13 year), follow-up time (6.1 ± 1.8 vs. 4.6 ± 2.1 months), LVEDV (154.3±50.8 vs.185.3±56.9 mL), and a trend for LVESV (112.4 ± 40.6 vs. 134.9 ± 47 mL, p = 0 .05). No differences were observed for EF, etiology of heart failure, and dyssynchrony measures between groups at baseline. Echo response rate was significantly ( p &lt; 0.05) greater in RVp (76%) than nRVp (57%). After adjusting for baseline differences, RVp had greater improvement in EF (14 ± 9 vs. 8 ± 7%, p &lt; 0.05) and LVESV (−33 ± 18 vs. −20 ± 21%, p &lt; 0.05). After adjustment for follow-up time, no difference was observed for change in dyssynchrony between groups. Conclusion: RVp patients upgraded to CRT exhibit greater improvements in systolic function and ventricular remodeling as compared to nRVp patients.

Biventricular Upgrading in Patients with Conventional Pacing System and Congestive Heart Failure:Results and Response Predictors

There are few studies on cardiac resynchronization therapy (CRT) in heart failure (HF) patients with preexisting right ventricular (RV) pacing. The purpose of this study was to determine the efficacy of CRT upgrading in RV-paced patients and the predictivity of electromechanical dyssynchrony parameters (EDP) evaluated by standard echocardiography (ECHO) and tissue Doppler imaging (TDI). Thirty-eight consecutive patients with HF [New York Heart Association (NYHA) class III or IV, LVEF < 35%], prior continuous RV pacing, and absence of atrial fibrillation were enrolled in the presence of a paced QRS > or = 150 ms and evaluated by ECHO and TDI. A responder was defined as a patient with a favorable change in NYHA class and neither HF hospitalization nor death, plus an absolute increase of LVEF > or = 10 units. At six-months follow-up, the whole study population had significant improvement in symptoms, systolic function, and QRS duration (P < 0.001); 32 (84%) patients had a favorable clinical outcome, 25 (66%) were considered responders according to the previous definition. Postimplant QRS was similarly reduced in both responders and nonresponders, whereas EDP had a significant improvement only in responders (P < 0.05). Using EDP, 23 (79%) patients were responders compared with 2 (22%) patients without mechanical dyssynchrony (P = 0.002). In HF patients with previous RV pacing, CRT is effective to improve clinical, functional outcome, and LV performance and to reduce electromechanical dyssynchrony in a large proportion of patients. Dyssynchrony evaluated by standard and TDI ECHO can be useful for CRT selection of paced patients.

The value of electrocardiographic signs in diagnosis previews of myocardial infarction in paced patients

The value of electrocardiographic signs in diagnosis previews of myocardial infarction in paced patients

Assessment of regional ventricular function by tissue Doppler technique in paced patients with different right ventricular pacing sites

Assessment of regional ventricular function by tissue Doppler technique in paced patients with different right ventricular pacing sites

Value of the 12-lead resting electrocardiogram for the diagnosis of previous myocardial infarction in paced patients

Aim This study was conducted to assess the clinical value of the 12-lead electrocardiogram (ECG) for the diagnosis of previous myocardial infarction (MI) in permanently paced patients. Methods A total of 107 unselected patients with permanent pacemakers were retrospectively studied and divided into 3 groups: group 1 (control group): 38 patients without a history of MI (mean age, 67 ± 16 years; 20 men; ejection fraction 63% ± 8%); group 2: 44 patients (mean age, 72 ± 11 years; 41 men) with documented previous MI (21 anterior, 23 inferior; ejection fraction 38% ± 13%; P < .0001 vs group 1); group 3: 25 patients (mean age, 71 ± 14 years; 24 men) with biventricular pacing for severe heart failure (16 ischemic, 9 nonischemic; ejection fraction 28% ± 8%; P = .001 vs group 2, P < .0001 vs group 1). A surface 12-lead ECG with full ventricular capture was used for analysis. Comparing group 1 and group 2, the sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of 5 criteria was calculated: (1) Cabrera's sign (notching in the ascending limb of the S wave in lead V 3, V 4, or V 5); (2) Chapman's sign (notching of the R wave in lead I, aVL, or V 6); (3) presence of a qR in lead I, aVL, or V 6; (4) notching of QRS in lead II, III, or aVF; (5) presence of a qR in lead II, III, or aVF. Results To detect prior MI, sensitivity was moderate for Cabrera's sign (63.6%) and poor for all other ECG criteria ranging from 9.1% to 40.9%. Specificity was relatively high for all ECG criteria ranging from 81.6% to 100%. Combining all 5 ECG signs increased sensitivity to 86.4%, with a specificity of 65.8% and an overall accuracy of 76.8% for the diagnosis of previous MI. None of the 5 criteria was particularly useful to assess the site of prior MI. In patients with biventricular pacing, the accuracy of the 5 ECG criteria was poor and the presence of a qR wave in lead I, aVL, or V6 appears nonspecific and related to pacing site. Conclusion The ECG diagnosis of previous MI in paced patients remains a difficult challenge but the presence of 1 or more of the aforementioned ECG criteria may be clinically useful to detect previous MI, suggesting that these ECG signs should be widely taught during medical training. However, in patients with biventricular pacing, these ECG signs are of no value.

High Prevalence of Sleep Apnea Syndrome in Patients With Long-Term Pacing

Cardiovascular diseases leading to pacemaker implantations are suspected of being associated with a high rate of undiagnosed sleep apnea syndrome (SAS). We sought to determine the prevalence and consequences of SAS in pacemaker patients according to pacing indications: heart failure, symptomatic diurnal bradycardia, and atrioventricular block. Ninety-eight consecutive patients (mean age, 64+/-8 years) not known to have sleep apnea were included; 29 patients were paced for dilated cardiomyopathy (29%), 33 for high-degree atrioventricular block (34%), and 36 for sinus node disease (37%). All underwent Epworth Sleepiness Scale assessment and polysomnography with the pacemaker programmed to right ventricular DDI pacing mode (lower pacing rate, 50 pulses per minute). SAS was defined as an apnea-hypopnea index > or = 10/h. Mean Epworth Sleepiness Scale was in the normal range (7+/-4), although 13 patients (25%) had an abnormal score > 11/h. Fifty-seven patients (59%) had SAS; of these, 21 (21.4%) had a severe SAS (apnea-hypopnea index > 30/h). In patients with heart failure, 50% presented with SAS (mean apnea-hypopnea index, 11+/-7) compared with 68% of patients with atrioventricular block (mean apnea-hypopnea index, 24+/-29) and 58% with sinus node disease (mean apnea-hypopnea index, 19+/-23). In paced patients, there is an excessively high prevalence of undiagnosed SAS (59%). Whether treating SAS would have changed the need for pacing is unknown. Treatment effects should be further evaluated particularly because these patients are less symptomatic than typical SAS patients. In any case, SAS should be systematically searched for in paced patients owing to potential detrimental effects on their cardiovascular evolution.

Long-Term Effects of Atrial Synchronous Ventricular Pacing on Systolic and Diastolic Ventricular Function in Patients with Normal Left Ventricular Ejection Fraction

Background: Atrial synchronous right ventricular pacing (VP) may compromise ventricular function in patients undergoing pacemaker implantation for atrioventricular block. We assessed the usefulness of tissue Doppler imaging (TDI) and color M-mode echocardiography in evaluating patients with VP, and examined the long-term effects of VP on ventricular function by echocardiographic indices and B-type natriuretic peptide (BNP) measurements. Methods: We studied 60 clinically stable elderly dual-chamber pacemaker recipients (mean age: 74 ± 9 years) who had normal left ventricular (LV) systolic function and on the long term the same cardiac rhythm, either intrinsic normal ventricular activation (IA) (n = 20), or VP (n = 40). Results: Paced patients, compared to patients with IA, had decreased stroke volume (p < 0.05) and a more depressed relaxation pattern, as indicated by decreased peak early mitral velocity (E)/peak atrial contraction velocity ratio and tissue Doppler imaging (TDI)-early transmitral diastolic velocity (Ea) measures (p < 0.05). Both groups presented similar BNP levels and LV filling pressures, as assessed by E/Ea and E/early diastolic transmitral flow propagation velocity. In VP patients, age (β = 0.31), Ea (β = –0.28) and E/Ea (β = 0.32) emerged as independent predictors of BNP levels. Conclusions: VP is associated with reduced LV systolic function and signs of impaired relaxation. Elevated BNP levels in elderly VP patients with normal ejection fraction may be predicted by TDI signs of LV diastolic dysfunction.

Upgrading from Single Chamber Right Ventricular to Biventricular Pacing in Permanently Paced Patients with Worsening Heart Failure: The RD‐CHF Study

Biventricular (BiV) stimulation lowers morbidity and mortality in patients with drug-refractory congestive heart failure (CHF), depressed left ventricular (LV) function, and ventricular dyssynchrony in absence of indication for permanent cardiac pacing. This pilot, single-blind, randomized, cross-over study examined the safety and efficacy of upgrading conventional pacing systems to BiV stimulation in patients with advanced CHF. We included 56 patients in New York Heart Association (NYHA) functional classes III or IV despite optimal drug treatment and ventricular dyssynchrony (interventriclar delay > 40 ms or LV preejection delay > 140 ms) in need of pacemaker replacement. We compared the patients' functional status, arrhythmias, and standard echocardiographic measurements during 3 months of conventional, single right ventricular (RV) versus 3 months of BiV stimulation. There were 44 patients in the cross-over phase. QRS duration was shortened by 23% and LV preejection delay by 16% with BiV stimulation. NYHA functional class, 6-minute hall walk and quality of life score were significantly improved with BiV stimulation compared with single RV pacing by 18%, 29%, and 19%, respectively. No significant difference was observed in the ventricular arrhythmia burden or LV reverse remodeling between the 2 periods. This pilot study showed that upgrading from RV pacing to BiV pacing significantly improves symptoms and exercise tolerance in chronically paced patients with advanced CHF and mechanical dyssynchrony.