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Query: UMLS:C0018801 (heart failure)
 72,216 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This report describes a woman with hypertrophic obstructive cardiomyopathy in whom initial hemodynamic improvement by dual chamber (DDD) pacing with short atrioventricular delay was excellent, but severe mitral regurgitation developed during the subsequent follow-up period, resulting in refractory congestive heart failure. There were two possible explanations for the origin of the complicating mitral regurgitation in this patient: pacing-induced semiclosure of the mitral valve, or left ventricular asynchrony caused by right ventricular pacing. Heart failure in patients with hypertrophic obstructive cardiomyopathy who undergo placement of a DDD pacemaker to improve not only mitral regurgitation but also heart failure symptoms can be associated with systolic mitral regurgitation as the cause of failure in DDD pacing therapy.
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PMID:Pacemaker-induced mitral regurgitation as a cause of refractory congestive heart failure during pacing therapy in a patient with hypertrophic obstructive cardiomyopathy. 1659 49

In DDD pacing, the left-ventricular electromechanical latency period defines the duration between premature ventricular stimulation and the prematurely ending left-atrial contribution to left-ventricular filling. It has to be considered in diastolic AV delay optimization. Individual duration of this parameter seemed to reflect the ventricular function. Therefore, we compared the left-ventricular electromechanical latency period due to right ventricular stimulus with the documented ejection fraction of two groups, 33 congestive heart failure patients carrying biventricular systems and 13 right ventricular paced bradycardia patients. A mean latency period of 168+/-26 ms was found in the heart failure patients (ejection fraction: 25+/-5%) which was significantly longer (p=0.0039) compared to the bradycardia patients (ejection fraction: 51+/-12%) with a mean latency of 119+/-13 ms. Thus, an increasing latency period during right ventricular DDD pacing therapy indicates decreasing ejection fraction. A cut-off interval of 135 ms allowed the discrimination of 93% of our patients as having an individual ejection fraction of either up to 35% or above. Thus, the left ventricular electromechanical latency period can be used as an additional parameter indicating the necessity to upgrade from right to biventricular DDD pacing.
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PMID:[Left ventricular electromechanical latency period is an additional indicator to upgrade from right to biventricular DDD pacing]. 1659 20

A 1.8-year-old male required a conventional DDD pacemaker for an atrioventricular block after congenital heart surgery. Five years later, heart failure due to left ventricular (LV) dyssynchrony progressed and we performed cardiac resynchronization therapy (CRT). Long-term echocardiographic follow-up showed that LV shortening fraction had improved within the first year after CRT, and LV end diastolic dimension had decreased after the first year. During LV remodeling (1-24 months after CRT), the QRS duration shortened without a change in the JT and T (peak-end) interval. The New York Heart Association class improved from III to I during the 2.3-year follow-up.
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PMID:Pediatric cardiac remodeling after cardiac resynchronization therapy. 1683 84

A three-dimensional electroanatomic bipolar voltage map of the right atrium was performed in a 20-year-old patient with functional single-ventricle physiology after a classic Fontan-type operation who presented with clinical signs of heart failure, a dilated right atrium, protein-losing enteropathy, and sinus node dysfunction. Previous pacemaker upgrading to a DDD system using a transvenous right atrial lead had failed due to insufficient sensing and pacing function. The voltage map showed large zones of scarring and low-amplitude signals. Consecutively, conversion to an extracardiac total cavopulmonary connection (TCPC) together with a pacing lead insertion into the left atrium was performed successfully.
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PMID:Three-dimensional electroanatomic voltage map-guided treatment of a patient with a failing atriopulmonary fontan circulation. 1732 36

Marked first-degree AV block (PR> or =0.30 s) can produce a clinical condition similar to that of the pacemaker syndrome. Clinical evaluation often requires a treadmill stress test because patients are more likely to become symptomatic with mild or moderate exercise when the PR interval cannot adapt appropriately. Uncontrolled studies have shown that many such symptomatic patients with normal left ventricular (LV) function improve with conventional dual chamber pacing (Class IIa indication). In contrast, marked first-degree AV block with LV systolic dysfunction and heart failure is still a Class IIb indication, a recommendation that is now questionable because a conventional DDD(R) pacemaker would be committed to right ventricular pacing (and its attendant risks) virtually 100% of the time. It would seem prudent at this juncture to consider a biventricular DDD device in this situation. Patients with suboptimally programmed pacemakers may develop functional atrial undersensing because the P wave tends to migrate easily into the postventricular atrial refractory period (PVARP). Retrograde vetriculoatrial conduction block is uncommon in marked first-degree AV block so a relatively short PVARP can often be used at rest with little risk of endless loop tachycardia. The usefulness of a short PVARP may be negated by special PVARP functions in some pulse generators designed to time out a long PVARP at rest and a gradually shorter one with activity. First-degree AV block during cardiac resynchronization therapy (CRT) predisposes to loss of ventricular resynchronization during biventricular pacing because it favors the initiation of electrical "desynchronization" especially in association with a relatively fast atrial rate and a relatively slow programmed upper rate. Patients with first-degree AV block have a poorer outcome with CRT than patients with a normal PR interval, a response that may involve several mechanisms. (1) The long PR interval may be a marker of more advanced heart disease. (2) Patients with first-degree AV block may experience more episodes of undetected "electrical desynchronization". (3) "Concealed resynchronization" whereupon ventricular activation in patients with a normal PR interval may result from fusion of electrical wavefronts coming from the right bundle branch and the impulse from the LV electrode. The resultant hemodynamic response may be superior because the detrimental effects of right ventricular stimulation (required in the setting of a longer PR interval) are avoided.
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PMID:First-degree atrioventricular block. Clinical manifestations, indications for pacing, pacemaker management & consequences during cardiac resynchronization. 1733 13

The EVADEF registry enrolled 2296 patients implanted with a defibrillator between june 2001 and june 2003 and followed up 24 months. Their main characteristics were the following: their mean age was 60+/-15S years, they were male in 86 %. Their left ventricular ejection fraction was 38.9 +/- 15.9 %. They were in NYHA class I or II for 83.8% of them, in class Ill for 14.7% and in class IV for only 1.5%. Secondary prevention indications concerned 82.1%, primary prevention 18.3%. Underlying cardiopathies were coronary artery disease in 61.3%, dilated cardiomyopathies in 15.9%. In a group of 7.1% there was no underlying heart disease. The implanted devices were VVI in 48.3%, DDD in 42.9%, biventricular pacemaker with defibrillator in 8.3% and dual defibrillator in 0.5%. Periprocedure complications concerned 13.8%. The most frequently reported was the presence of an haematoma. Periprocedure mortality concerned 8 patients, i.e. 0.3% of the total cohort. Mortality was 7.2% at 1 year and 11.3% at 2 years. Among the 274 deaths, a majority was due to heart failure (42%), arrhythmic storms represented only 6.2% of deaths. Hopefully it is likely that in the future association of cardiac resynchronization therapy to defibrillator will be able to decrease this death rate due to heart failure.
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PMID:[EVADEF registry, main data]. 1747 83

From 1996 to 2002 primary implantations of pacing systems because of bradysystolic disturbances of cardiac rhythm and conduction had been carried out in 311 patients. Indications were disturbances of atrioventricular conduction in 168 and sick sinus syndrome in 143 patients. According to type of permanent pacing patients were divided into 3 groups: with single-chamber ventricular on demand pacing (VVI, n=215), with single-chamber atrial pacing (AAI, n=39), and with dual-chamber pacing (DDD, n=57). As characteristics illustrating long term clinical results of permanent pacing we used development of the pacemaker syndrome; development of permanent atrial fibrillation; risk of thromboembolic complications and strokes; progression of heart failure; total, cardiovascular mortality and their structure; 7 year survival.
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PMID:[Clinical efficacy of permanent cardiac pacing in patients with bradysystolic forms of disturbances of cardiac rhythm and conduction]. 1826 Sep 96

In patients with frequent right ventricular stimulation, worsening of heart failure and atrial fibrillation may occur. Avoidance of unnecessary right ventricular pacing is a major requirement for pacemaker selection and programming in patients with sinus node disease or intermittent AV block. In dual chamber pacemakers this goal can be achieved by programming a long AV delay or an AV delay hysteresis. Algorithms that allow AAI pacing in a dual chamber pacing mode and change to DDD mode in case of high degree AV block are a new attempt to avoid unnecessary right ventricular pacing. The article describes various strategies to avoid unnecessary ventricular pacing and discusses their advantages and disadvantages.
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PMID:[Avoidance of ventricular pacing in patients with sinus node disease or intermittent AV block]. 1833 Jun 70

Biventricular pacing has been suggested in end-stage heart failure. We present a 59-year-old patient undergoing second re-do CABG (coronary artery bypass graft) and carotid artery endarterectomy. Ejection fraction was 15%, QRS-width 175 ms. Following the carotid and CABG procedure, an implanted single-chamber ICD (implantable cardioverter defibrillator) was upgraded to permanent biventricular DDD pacing by implantation of one epicardial left ventricular and one epicardial atrial electrode. At follow-up two months postoperatively ejection fraction had significantly improved to 45%, the patient underwent stress test with adequate load and reported a good quality of life.
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PMID:Permanent biventricular ICD-implantation in a heart failure second re-do-CABG patient: a case report. 1914 86

Hypertrophic cardiomyopathy (HCM) is classified as a primary cardiomyopathy. HCM is a clinically heterogeneous but relatively common autosomal dominant genetic heart disease that probably is the most frequently occurring cardiomyopathy. HCM is characterized morphologically and defined by a hypertrophied, nondilated left ventriculum (LV) in the absence of another systemic or cardiac disease that is capable of producing the magnitude of wall thickening evident (e.g., systemic hypertension, aortic valve stenosis). Most HCM patients have the propensity to develop dynamic obstruction to LV outflow under resting or physiologically provocable conditions, produced by systolic anterior motion of the mitral valve with ventricular septal contact. The phenotypic features of HCM may develop at any age from infancy to adulthood, and are characterized by a great heterogeneity in the extent, magnitude, and distribution of left ventricular hypertrophy. Hypertrophic obstructive cardiomyopathy (HOCM) often leads to heart failure, severe ischemia, severe symptoms and death. Determination of the exact site of the hypertrophy and of the obstruction of the left ventricular outflow tract, in asymmetric septal hypertrophy, establishes which is the best treatment strategy. In the treatment of HOCM, drug therapy with negatively inotropic drugs, percutaneous transluminal septal myocardial ablation by alcohol-induced septal branch occlusion, surgical myectomy and DDD pacemaker therapy are considered the therapeutical options. We present a case of an obstructive hypertrophic cardiomyopathy in an 84-year-old Italian woman with a left ventricular outflow tract (LVOT) peak gradient with the Valsalva maneuver of 188 mm Hg and with a history of first episode of syncope.
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PMID:Revelation of an obstructive hypertrophic cardiomyopathy in an elderly patient. 1918 3


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