Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0018799 (heart disease)
 34,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The association of drinking water arsenic and mortality outcome was investigated in a cohort of residents from Millard County, Utah. Median drinking water arsenic concentrations for selected study towns ranged from 14 to 166 ppb and were from public and private samples collected and analyzed under the auspices of the State of Utah Department of Environmental Quality, Division of Drinking Water. Cohort members were assembled using historical documents of the Church of Jesus Christ of Latter-day Saints. Standard mortality ratios (SMRs) were calculated. Using residence history and median drinking water arsenic concentration, a matrix for cumulative arsenic exposure was created. Without regard to specific exposure levels, statistically significant findings include increased mortality from hypertensive heart disease [SMR = 2.20; 95% confidence interval (CI), 1.36-3.36], nephritis and nephrosis (SMR = 1.72; CI, 1.13-2.50), and prostate cancer (SMR = 1.45; CI, 1.07-1. 91) among cohort males. Among cohort females, statistically significant increased mortality was found for hypertensive heart disease (SMR = 1.73; CI, 1.11-2.58) and for the category of all other heart disease, which includes pulmonary heart disease, pericarditis, and other diseases of the pericardium (SMR = 1.43; CI, 1.11-1.80). SMR analysis by low, medium, and high arsenic exposure groups hinted at a dose relationship for prostate cancer. Although the SMRs by exposure category were elevated for hypertensive heart disease for both males and females, the increases were not sequential from low to high groups. Because the relationship between health effects and exposure to drinking water arsenic is not well established in U.S. populations, further evaluation of effects in low-exposure populations is warranted.
 ...
PMID:Drinking water arsenic in Utah: A cohort mortality study. 1181 97

We performed simultaneous catheter mapping of right and left atrial regions at onset and during sustenance of spontaneous atrial fibrillation (AF) in patients with ischemic and/or hypertensive heart disease. Seventeen patients with structural heart disease had spontaneous and electrically induced AF episodes mapped from their onset simultaneously in multiple right and left atrial regions. Atrial premature complexes (APCs) that initiated spontaneous AF had coupling intervals ranging from 260 to 400 ms (mean 332 +/- 61), most commonly arising from the lateral right atrium (31%), right atrioventricular junction (13%), atrial septum (6%), superior left atrium (25%), or inferior left atrium (25%). APC morphology on surface electrocardiograms did not correlate with origin in specific atrial regions. The earliest regions of atrial activation for the first AF cycle were the lateral right atrium (n = 5), superior left atrium (n = 4), distal or mid coronary sinus (n = 4), atrial septum (n = 2), and right atrioventricular junction at the His bundle location (n = 2). Spontaneous AF at onset usually showed discrete but irregular electrograms at virtually all right and left atrial sites mapped, with a reproducible region of AF initiation in all 8 patients with multiple events. The region of earliest atrial activation at spontaneous AF onset was in close proximity to the APC origin in 15 of 16 patients (94%), and 39 of 40 episodes (97%) mapped. Stable patterns of right and left atrial activation were observed at AF onset in 14 patients. Induced AF elicited with right atrial stimulation demonstrated different sites of earliest regional atrial activation at onset compared with spontaneous AF events in 4 of 8 patients. However, discrete intracardiac electrograms were also present in induced AF in all of the mapped atrial regions. Furthermore, the site of extrastimulus delivery in induced AF was also found to be in close proximity to the earliest region of atrial activation for the first AF beat. We conclude that spontaneous AF is initiated by APCs arising in different right or left atrial regions in patients with structural heart disease and the initial region of atrial activation in AF is in proximity to the region of APC origin. Organized and repetitive electrical activation is frequently observed in both right and left atria at AF onset. Although electrically induced AF may have different activation patterns than spontaneous AF at onset in many patients, both types of AF demonstrate organization and earliest atrial activation in proximity to the initiating APC.
 ...
PMID:Regional endocardial mapping of spontaneous and induced atrial fibrillation in patients with heart disease and refractory atrial fibrillation. 1053 4

The clinical electrophysiologic study of atrial fibrillation [AF] has recently progressed from static characterization of the substrate to the dynamic investigation of both induced and spontaneous AF in man. Prior studies have demonstrated inhomogeneity and greater dispersion of atrial refractoriness in patients with AF, but recently atrial electrical remodeling with consequent abbreviation of atrial refractory periods has also been reported. Yet further experimental observations have suggested the existence of additional arrhythmogenic mechanisms for certain AF subsets. These include studies that have demonstrated a stable atrial flutter circuit in one atrium with fibrillatory conduction or a focal atrial tachyarrhythmia arising commonly in the left atrium. Efforts at catheter mapping of AF are now in progress. New mapping techniques and novel devices are currently being employed. We have performed catheter mapping simultaneously in right and left atrial sites at onset and during sustained pacing-induced and spontaneous AF in patients with ischemic and/or hypertensive heart disease. Atrial premature complexes that initiated spontaneous AF typically had coupling intervals ranging from 260 to 400 ms and most frequently arose in the crista terminalis, right atrioventricular junction or superior left atrium. AF at onset showed discrete electrograms at virtually all right and left atrial regions mapped and the region of earliest atrial activation during AF was in close proximity to the premature complexes in over 90% of patients. The regional atrial activation sequence for the first 10 AF beats demonstrated stable or unstable patterns in individual patients. In contrast to spontaneous AF, the initial arrhythmia of induced AF was seen to have a significantly different site of earliest atrial activation but similar discrete electrograms in different atrial regions. However, as with spontaneous AF, the site of extrastimulus delivery was in close proximity to the first induced beat. We conclude that regional catheter mapping of AF is feasible and safe in man and organized electrical activity is frequently observed at AF onset in patients with heart disease. Both right and left atrial regions can be the source of atrial premature complexes and at the onset of spontaneous AF. Induced AF may have differing activation patterns than spontaneous AF but both demonstrate earliest activation in proximity to the initiating atrial premature complex. These findings may help explain therapeutic benefits of right and left atrial interventions and pacing therapies in AF.
 ...
PMID:Catheter mapping of spontaneous and induced atrial fibrillation in man. 1059 Apr 85

BACKGROUND: Sotalol has combined type II and type III antiarrhythmic properties. Although the beta-blocking action of sotalol is thought to contribute to its antiarrhythmic actions, few data are available from direct comparative clinical trials with pure beta-blocking drugs. METHODS AND RESULTS: In this double-blind, randomized, multicenter, placebo-controlled, parallel study, we have compared the antiarrhythmic efficacy and safety of treatment with sotalol vs propranolol in 181 patients with organic heart disease and frequent (>30 ventricular premature complexes [VPCs]/h) repetitive ventricular premature complexes. Eighty-seven were randomized to receive sotalol and 94 received propranolol. The demographic and clinical characteristics of the two groups were identical, and the majority of patients had coronary artery disease or hypertensive heart disease. Most patients had a long-standing history (>5 years) of ventricular arrhythmias and, in a significant proportion, antiarrhythmic therapy with other drugs had failed in the past. After withdrawal of all antiarrhythmic drugs and 1 week of placebo, qualified patients were randomized to sotalol (320 mg/day) or propranolol (120 mg/day). patients not achieving adequate response were given higher doses of sotalol (640 mg/day) or propranolol (240 mg/day)At baseline, both groups had comparable frequency of total VPCs/hour (274/h and 255/h for sotalol and propranolol groups, respectively) which was reduced to 71 VPCs/h and 109/VPCs/h, respectively, at the end of phase 1. At final evaluation there was a significantly greater response to sotalol as demonstrated by 80% reduction in VPCs/hour with sotalol compared with only 50% reduction noted in the propranolol group. Adequate therapeutic response was also achieved in a significantly greater percentage of patients on sotalol compared with propranolol (56% vs 29%, P =.02). Sotalol was also superior to propranolol in suppressing the VT events/day during phase 1 (89% vs 78% reduction in VT events/day, P <.05). Sotalol was more effective than propranolol in all subgroups and in patients with heart rate <75 beats per minute. CONCLUSIONS: Sotalol is more powerful than propranolol in suppressing ventricular arrhythmias documented on Holter recordings. The superiority of sotalol appears to be related to its combined class II and class III antiarrhythmic actions.
 ...
PMID:Sotalol Is More Powerful Than Propranolol in Suppressing Complex Ventricular Arrhythmias. 1068 67

Pictures certainly are worth a thousand words in the case of the structure of the connective tissue skeleton of normal and diseased myocardium. This report reviews the connective tissue matrix of the normal human myocardial tissue and the pathological myocardial fibrosis in left ventricular hypertrophy due to chronic arterial hypertension in humans and in human chronic chagasic myocarditis. The myocardial connective tissue matrix was studied employing a cell-maceration method that removes the myocardial tissue non-fibrous elements, and leaves behind a non-collapsed matrix, thus allowing a better three-dimensional view. Such information extends our knowledge of the expression of interstitial myocardial fibrous tissue in normal hearts and in hypertensive left ventricular hypertrophy and chronic chagasic myocarditis. The progressive accumulation of interstitial collagen fibers in both chronic cardiac diseases may be expected to decrease myocardial compliance and disrupt synchronous contractions of the ventricles during systole, contributing to a spectrum of ventricular dysfunction that involve either the diastolic or systolic phase of the cardiac cycle or both. In hypertensive heart disease myocardial fibrosis can be also implicated in the genesis of ventricular dysrhythmias, possible causes of sudden death among chronic hypertensive patients. Regarding chronic chagasic myocarditis, myocardial fibrosis is probably implicated in the genesis of malignant ventricular tachyarrhythmias (ventricular tachycardia and ventricular fibrillation), major causes of sudden death among patients with chronic Chagas' heart disease. The collagen distribution could interfere on the electrical properties of the myocardium. Fibrosis can block the cardiac impulse that may recycle (re-entry) through an alternative route and could slow conduction. In addition, the thick collagenous septa encompassing muscle fiber bundles could interfere with lateral impulse conduction, which would favor re-entry. Moreover, the methodology used is a useful tool to study the spatial organization of the collagen fibrils of the myocardium under normal and pathological conditions.
 ...
PMID:Connective tissue skeleton in the normal left ventricle and in hypertensive left ventricular hypertrophy and chronic chagasic myocarditis. 1143 16

Complete atrioventricular block occurred during spinal and subsequent general anaesthesia in a 74-year-old patient with known arterial hypertension but without heart conduction abnormality. Drug therapy and intermittent transcutaneous pacing was successful. A decrease of arterial pressure by more than 40% preceded the heart blockade in the course of both events. Subsequent cardiologic examination revealed evidence of a discrete hypertensive heart disease. Relative ischemia of the atrioventricular region during anaesthesia was suggested as an aetiology. When the patient presented for the next operation, again general anaesthesia was applied, and invasive arterial blood pressure monitoring as well as catecholamine support were used and no further atrioventricular blockade occurred. The case demonstrates the possible recurrence of an intraoperative complete atrioventricular blockade in an older patient without pre-existing conduction abnormalities and only minor signs of heart disease, irrespective of the anaesthesia technique. Under these circumstances transcutaneous pacing should always be in place. Maintenance of coronary perfusion pressure is essential and invasive blood pressure monitoring is recommended.
 ...
PMID:[Complete heart block after spinal and general anaesthesia]. 1271 35

Atrial fibrillation is now the most common cardiac arrhythmia for which a patient is hospitalized. Clinically, it presents in a form that is paroxysmal, persistent, or permanent and may be symptomatic or asymptomatic, occurring in the setting of either no cardiac disease ("lone atrial fibrillation") or, most often, in association with an underlying disease. Atrial fibrillation is associated with a 2-fold increase in mortality and, in the United States alone, causes over 75,000 cases of stroke per year. The annual prevalence of stroke is 5% to 7%, but the use of adequate anticoagulation can reduce this to less than 1%. Atrial fibrillation is a disorder of the elderly, with almost equal prevalence in men and women. In the United States, 80% of atrial fibrillation occurs in patients over the age of 65 years, and its prevalence tracks that of heart failure, which may be the cause, as well as the result, of the arrhythmia. Both conditions are increasing in epidemic proportions in the aging population. The most common causes of atrial fibrillation are hypertensive heart disease, coronary artery disease, and heart failure with a miscellany of lesser conditions, with about 10% lacking structural heart disease. Unlike other supraventricular arrhythmias, cure by the use of catheter ablation and surgical techniques has not been a reality except in a relatively small number of cases. However, restoration and maintenance of sinus rhythm remain the initial goal of therapy for most patients. Pharmacologic approaches remain the mainstay of therapy for rate control and anticoagulation as well as for maintenance of sinus rhythm following pharmacological or electrical conversion. The changing epidemiology of atrial fibrillation is highlighted, with the focus on its conversion by the use of newer and novel antifibrillatory agents relative to the mechanisms of the arrhythmia, to restore the stability of sinus rhythm.
 ...
PMID:Atrial fibrillation: epidemiologic considerations and rationale for conversion and maintenance of sinus rhythm. 1450 50

In this study, a medical diagnosis decision support system based on hybrid genetic algorithm has been established to support the diagnosis of five common heart diseases (coronary heart disease, rheumatic valvular heart disease, hypertensive heart disease, chronic cor pulmonale and congenital heart disease). A heart disease database consisting of 352 samples was used for constructing and testing the performance of system. Cross-validation of the experimental results indicate that the system we established shows high capability of classifying these five kinds of heart diseases, the mean accuracy of classification is as high as 90.6%, and the user accuracy and procedure accuracy of each disease are both above 85.0%, showing great application prospect of supporting heart diseases diagnosis in clinics.
 ...
PMID:[Study on medical diagnosis decision support system for heart diseases based on hybrid genetic algorithm]. 1514 64

To determine which of the many clinical parameters routinely collected influence mortality in patients with low left ventricular ejection fraction (LVEF) (< 45% at radionuclide ventriculography), 128 elderly patients (mean age 79 +/- 3 years) with various heart diseases were prospectively followed for 3 years. Twenty-eight-percent had coronary heart disease, 16% hypertensive heart disease, 7% valvular heart disease. The remaining 62 patients (48%) made up a group comprising patients with primitive cardiomyopathy, cor pulmonary with no evidence of coronary heart disease, valvular disease or hypertensive heart disease. Thirty-four-percent of all patients were classified as having congestive heart failure (CHF). Age, sex and 37 clinical variables were analyzed using a Cox proportional model. Forty-four patients died, 36 (82%) of sudden cardiac death. Ten characteristics at study entry predicted an increased mortality risk: S3 gallop, number of clinical signs >or= 3, LVEF <or= 25%, New York Heart Association (NYHA) class >or= III, dyspnea, digoxin treatment, rales, number of symptoms >or= 4, asthenia, associated pulmonary disease. Long-term survival of very elderly patients with low ejection fraction is related to the functional capacity, the severity of symptoms and the number of clinical signs. Moreover a LVEF <or= 25% selects a subgroup of patients at higher risk. Our results suggest that these variables may influence the long-term survival of elderly patients with heart disease. Further studies with a greater number of patients are necessary to better delineate the prognostic value of the clinical and instrumental variables routinely collected in these patients.
 ...
PMID:Clinical determinants of long-term mortality in elderly patients with heart disease. 1537 99

The aim of this clinical crossover study was to elucidate the effects of atrioventricular (AV) synchronous pacing on cardiac function in patients with sick sinus syndrome (SSS). Thirty SSS patients, each with dual chamber pacemaker (DDD), were enrolled and divided into two groups based on echocardiographic findings. Group A (n = 16) had hypertensive heart disease (wall thickness 11 approximately 12 mm) or mitral or aortic regurgitation (Grade I or II). Group B (n = 14) had no organic heart disease. Three successive 3-month pacing periods were tested. For the first 3 months, long AV delay that achieved > 80% ventricular sensing was chosen. For the next 3 months, AV delay was abbreviated to achieve > 80% ventricular pacing at an optimal AV interval. For the final 3 months, the first setting was resumed. At the end of each period, M mode echocardiography, pulsed-Doppler study, and measurement of plasma brain natriuretic peptide (BNP) level were conducted. In both groups, echocardiographic parameters were not significantly changed during the evaluation. In group A, plasma BNP level was significantly higher at the end of the short AV delay period than at the long AV delay period (P = 0.009), while in group B it did not differ during each period. AV synchronous pacing (> 80% ventricular pacing) in the SSS patients with a DDD pacemaker implanted could increase the ventricular load, and it is better to preserve the spontaneous QRS with the DDD mode with prolonged AV delay in patients with mild hypertensive or valvular disease.
 ...
PMID:Clinical significance of preserving spontaneous QRS wave in the therapy of DDD pacing for sick sinus syndrome. 1546 10


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>