Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018801 (heart failure)
 72,216 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The aim of this study was to assess the long term efficacy of DDD pacing mode in selected patients with idiopathic dilated cardiomyopathy (IDCM) and drug refractory heart failure. The patients were evaluated according to the long term alteration of the sympathovagal balance (SVB). Patients with IDCM were considered eligible for DDD pacing if during temporary VDD pacing a 15% or more increase in the resting cardiac output was demonstrated. From the 29 patients studied, finally 20 patients (15M, 5F, 69 +/- 10 years) fulfilled the aforementioned criterion and therefore were considered candidates for permanent DDD pacing (NYHA class: 3.5 +/- 0.3, Ejection fraction: 27 +/- 7%, Resting cardiac index (CI) 2.6 +/- 0.4 l/min). The ECG of the patients demonstrated LBBB in 13, RBBB in 4 and RBBB + LAH in 3, with a PR interval of 232 +/- 28 ms and QRS duration of 138 +/- 15 ms. The pacemaker was programmed at 40-150 bpm, and AV delay of 105 +/- 20 ms. The lower heart rate programmed, in conjunction with the heart failure state of these patients, was responsible for essentially continuous atrial tracking, ventricular pacing. We evaluated the SVB in the pre- and post-implant periods (3rd and 6th month), using the hourly power spectral analysis (PSA) of heart rate variability during 24 hour Holter monitoring. As SVB we considered the ratio: low (0.04-0.15 Hz) to high frequency (0.15-0.40 Hz). We compared the SVB (LF/HF) during the day and night time for the pre- and post-implant periods. Post-pacing, the NYHA class was significantly improved (2.9 +/- 0.2 and 2.7 +/- 0.3 the 3rd and 6th month respectively). The mean heart rate was 78 +/- 8 bpm in the 3rd and 80 +/- 7 bpm in the 6th month postoperatively, which was lower than the 84 +/- 9 bpm preoperatively, but this difference did not reach statistical significance. During the night time the LF/HF decreased from 1.45 +/- 0.2 (LF: 7.19 +/- 0.43, HF: 4.95 +/- 0.54) in the pre-implant period to 0.9 +/- 0.09 (p < 0.001) (LF: 6.96 +/- 0.63, HF: 7.73 +/- 0.48) in the 3rd month. No further changes were observed in the 6th month (0.82 +/- 0.05, p = NS) (LF: 6.83 +/- 0.51, HF: 8.53 +/- 0.86) compared to the 3rd month. During the day time the LF/HF decreased from 1.5 +/- 0.5 (LF: 7.87 +/- 0.67, HF: 5.24 +/- 0.32) to 1.43 +/- 0.6 (p = NS) (LF: 7.34 +/- 0.71, HF: 5.24 +/- 0.42) in the 3rd month and to 1.41 +/- 0.09 in the 6th month (p = NS) (LF: 7.51 +/- 0.74, HF: 5.36 +/- 0.63). Comparing the LF/HF of day and the night time period, while in the pre-implant period there was no significant difference (1.5 +/- 0.5 vs 1.45 +/- 0.2, p = NS), the difference became significant in the 3rd (1.43 +/- 0.6 vs 0.9 +/- 0.09, p < 0.001) and 6th month (1.41 +/- 0.09 vs 0.82 +/- 0.05, p < 0.001). In conclusion, DDD pacing with individualized AV delay as an adjunct therapy could be a valuable method in selected patients with IDCM and drug refractory heart failure. DDD pacing improves the SVB over the long term. This improvement is attributed to sympathetic activity withdrawal and is more pronounced during night and less during day time.
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PMID:Modulation of the sympathovagal balance in drug refractory dilated cardiomyopathy, treated with permanent atrioventricular sequential pacing. 1080 27

Disturbance of normal AV synchrony and dyssynchronous ventricular contraction may be deleterious in patients with otherwise compromised hemodynamics. This study evaluated the effect of hemodynamically optimized temporary dual chamber pacing in patients after surgery for congenital heart disease. Pacing was performed in 23 children aged 5 days to 7.7 years (median 7.3 months) with various postoperative dysrhythmias, low cardiac output, and/or high inotropic support and optimized to achieve the highest systolic and mean arterial pressures. The following four pacing modes were used: (1) AV synchronous or AV sequential pacing with individually optimized AV delay in 11 patients with first- to third-degree AV block; (2) AV sequential pacing using transesophageal atrial pacing in combination with a temporary DDD pacemaker for atrial tracking and ventricular pacing in three patients with third-degree AV block and junctional ectopic tachycardia, respectively, who had poor signal and exit block on atrial epicardial pacing wires; (3) R wave synchronized atrial pacing in eight patients with junctional ectopic tachycardia and impaired antegrade AV conduction precluding the use of atrial overdrive pacing; (4) Atrio-biventricular sequential pacing in two patients. Pressures measured during optimized pacing were compared to baseline values at underlying rhythm (13 patients with first-degree AV block or junctional ectopic tachycardia) or during pacing modes commonly used in the given clinical situation: AAI pacing (1 patient with slow junctional rhythm and first-degree AV block during atrial pacing), VVI pacing (2 patients with third-degree AV block and exit block and poor sensing on epicardial atrial pacing wires) and dual-chamber pacing with AV delays set to 100 ms (atrial tracking) or 150 ms (AV sequential pacing) in 7 patients with second- to third-degree AV block and functional atrial pacing wires. Optimized pacing led to a significant increase in arterial systolic (mean) pressure from 71.5 +/- 12.5 (52.3 +/- 9.0) to 80.5 +/- 12.2 (59.7 +/- 9.1) mmHg (P < 0.001 for both) and a decrease in central venous (left atrial) pressure from 12.3 +/- 3.4 (10.5 +/- 3.2) to 11.0 +/- 3.0 (9.2 +/- 2.7) mmHg (P < 0.001 and < 0.005, respectively). In conclusion, several techniques of individually optimized temporary dual chamber pacing leading to optimal AV synchrony and/or synchronous ventricular contraction were successfully used to improve hemodynamics in patients with heart failure and selected dysrhythmias after congenital heart surgery.
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PMID:Hemodynamically optimized temporary cardiac pacing after surgery for congenital heart defects. 1096 47

Numerous studies demonstrated the superiority of atrial based pacing modes (AAI/R, DDD/R) in the pacemaker therapy of sinus node disease. They reduce mortality, the incidence of atrial fibrillation and the risk for heart failure and increase quality of life, but there is still debate about the most appropriate mode of pacing. The AAI-mode carries the risk of high degree AV-block and the possible occurence of atrial fibrillation with slow ventricular response, demanding ventricular stimulation. DDD-pacemakers, however, are more complex and expensive and the stimulation in the apex of the right ventricle results in the loss of the normal activation sequence of the ventricles and can cause hemodynamic deterioration. Despite the lack of prospective randomized studies comparing the long term performance of the two pacing modes (AAI/R and DDD/R) many arguments plead in favour of a preferential use of AAI/R in patients eligible for permanent atrial pacing.
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PMID:[Sick sinus syndrome indication: AAI/R versus DDD/R]. 1113 33

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.
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PMID:Intermediate-term results of biventricular pacing in heart failure: correlation between clinical and hemodynamic data. 1113 7

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.
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PMID:Hemodynamic assessment of right, left, and biventricular pacing by peak endocardial acceleration and echocardiography in patients with end-stage heart failure. 1113 10

Although medical therapy is the primary therapy for patients with heart failure, the use of pacemakers to improve cardiac hemodynamics is under investigation. Despite promising initial results, controlled studies have not verified the benefit of application of VDD or DDD pacing to a nonselected population of severely symptomatic congestive heart failure (CHF) patients to simply shorten their atrioventricular (AV) delay. There is increasing interest in pacing the left side of the heart or simultaneously pacing the right and left ventricles. Early studies suggest that these techniques may produce favorable hemodynamic effects in patients with CHF. Controlled, randomized studies are now underway. Further, it has been shown that sudden cardiac death accounts for 50% of deaths in patients with CHF. The value of an implantable cardioverter defibrillator (ICD) in secondary prevention of sudden cardiac death is well established. The use of ICD for primary prevention of sudden cardiac death in patients with CHF is being actively evaluated. Several large multicenter trials are underway, some combined with biventricular pacing, and should provide useful data in the coming years.
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PMID:Pacemakers and defibrillators for congestive heart failure. 1117 68

Mounting evidence shows that elevated resting sinus rate is an independent predictor of cardiovascular morbidity and mortality in the general population, in elderly subjects, and in patients with myocardial infarction or hypertension. Therefore, a rather slow sinus rate appears to be a protecting factor acting through several mechanisms. The present contribution focuses on the relationship between sinus rate and heart failure. Its major objectives are to discuss whether in patients with heart failure a rather slow heart rate is advisable and whether a sinus bradycardia secondary to sinus node dysfunction can facilitate the development of heart failure. It has been reported that among patients with left ventricular dysfunction, increased sinus rate was a predictor of cardiovascular death at univariate analysis; however, a multivariate analysis to verify whether sinus rate was an independent predictor of mortality was not performed. Randomized trials carried out by utilizing beta-blockers or amiodarone in patients with heart failure showed that heart rate reduction by these drugs was a marker of their ability to reduce mortality. However, beta-blockers and amiodarone have additional pharmacological effects which interfere with the disease substrate. So, at present, though the results of these trials show that a rather slow sinus rate is advisable, we do not know whether in patients with heart failure sinus rate represents an independent predictor of mortality as in patients with myocardial infarction or hypertension and whether the reduction of sinus rate per se is beneficial. The results of the recent randomized THEOPACE trial showed, for the first time, that in a patient population with symptomatic sinus bradycardia (sinus rate < 50 b/min), an increase in heart rate, induced by DDD pacing or oral theophylline, reduced the incidence of overt heart failure. Therefore, sinus bradycardia seems to play a role in the genesis of heart failure. In a post-hoc analysis of the results of this trial it emerged that in the control (not treated) group, the subjects with sinus bradycardia more prone to develop heart failure were those of old age, about 80 years, with organic heart disease and severe chronotropic incompetence. However, this conclusion needs further validation.
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PMID:Development of heart failure in bradycardic sick sinus syndrome. 1121 7

The QRS widening by ventricular conventional pacing impairs the systolic and diastolic functions and increases mitral regurgitation. The aim of this study was to compare conventional pacing to an alternative stimulation mode with a narrower QRS using two leads in the RV. Thirty-nine (25 men, 14 women; mean age 60.1 +/- 15.1 years) dilated cardiomyopathy patients (Chagas' disease [n = 17], coronariopathy [n = 9], AV ablation for tachycardiomyopathy [n = 3], and other [n = 10]) with cardiac failure (NYHA 3.1 +/- 0.8), pacemaker indication, and chronic AV block (22 AF) had endocardial pacemaker implantations (27 Biotronik, 12 Guidant). Two RV leads (one septal, one conventional [RV apex] were connected, respectively, to the atrial and ventricular pacemaker plugs. After clinical stabilization they were studied under three stimulation modes in the same session: AAI (septal), VVI (conventional), and ventricular endocardial right bifocal stimulation (VERBS) (DDT/DVI/DDD = AV interval = 15/10 ms). In comparison to conventional pacing, VERBS increased ejection fraction (0.124), cardiac output (19.5%), and peak filling rate (31.0%), and decreased QRS duration (24.7%), left atrium area (11.9%), mitral regurgitation area (32.3%), the diastolic transmitral flow (E/A relation) (19.3%), and the propagation flow time (18.0%) from the mitral valve to the left ventricular apex (tE_col), (P < 0.05). The quality-of-life showed an impressive score reduction of 50.4%. The septal stimulation alone showed a less expressive benefit. In severe dilated cardiomyopathy with classic pacemaker indication, VERBS showed significantly better performance than the septal or the conventional stimulation alone. There was a good systolic and a remarkable diastolic improvement causing an important reduction in the quality-of-life score.
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PMID:Ventricular endocardial right bifocal stimulation in the treatment of severe dilated cardiomyopathy heart failure with wide QRS. 1586 64

The year 2002 was marked by the publication of several studies for which the results have above all brought confirmation but also disappointment. One of them has even revealed a new therapeutic approach. In patients affected by sinus dysfunction the MOST study has shown the absence of superiority of DDD stimulation over VVI stimulation in respect of death and cerebral vascular accidents. However, double chamber stimulation reduces the risk of atrial fibrillation, the signs of cardiac insufficiency and slightly improves the quality of life. In the field of multisite stimulation, the MIRACLE study has in patients with moderate to severe cardiac insufficiency confirmed the results of the MUSTIC study with a significant improvement relating to the 6 minute walking test, the NYHA class, the quality of life, and the ejection fraction. The 12 and 24 month follow up of patients included in the MUSTIC study has shown the persistence of the observed short term benefit. Hopes for prevention of atrial fibrillation by atrial stimulation piloted by special algorithms have not been confirmed by the results of the PIPAF study except for patients with predominantly spontaneous AV conduction. The significance of stimulation in disabling vaso-vagal syncope has been questioned by the publication of the results of the VPS 2 study. Cardiac stimulation could in the future constitute a new treatment for sleep apnoea syndrome because it has been reported that atrial overdrive significantly reduces the amount of central or obstructive apnoea.
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PMID:[The best of cardiac pacing in 2002]. 1261 61

After initial trials of conventional DDD pacing in dilated cardiomyopathies, the concept of multisite stimulation was introduced in 1994. This new indication of heart failure treatment is based on the correction of myocardial contraction and relaxation asynchronies. European pilot studies including few patients were followed by two multicenters randomized trials (MUSTIC and MIRACLE) that confirmed a significant improvement of functional capacity, quality of life and hemodynamic status. Intraventricular delay and QRS duration shortening seems to be the best predictor of clinical success. Patients with more depressed functional and hemodynamic status seems to benefit most from this therapeutic approach. Two studies (CARE HF and COMPANION) are still conducted which will provide further insight into the effectiveness in terms of prognosis of cardiac resynchronisation therapy in this patient population.
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PMID:[Bi-ventricular synchronous pacing and heart failure]. 1269 63


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