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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Calcium channel blocking drugs are a chemically heterogenous group, so it might be expected that their effects on vascular smooth muscle, cardiac contractility, and conduction tissue may differ. However, the majority of adverse reactions are predictable from their pharmacological actions and may be conveniently grouped in the following categories: 1) vasodilatation, 2) negative inotropic effects, 3) conduction disturbances, 4) gastrointestinal effects, 5) metabolic effects, and 6) drug interactions. Vasodilatory symptoms, namely, dizziness, headaches, flushing sensation, and palpitation, are more likely with nifedipine. Peripheral edema is also common with nifedipine, but the mechanism is uncertain. For a given degree of vasodilation, the greatest negative inotropic effect is seen with verapamil first, diltiazem second, and nifedipine last. Calcium channel blocking drugs are contraindicated in hypertensive patients with second and third degree heart block, sick sinus syndrome, and severe heart failure. Verapamil and diltiazem have a significant effect on cardiac conduction, whereas nifedipine, in therapeutic doses, does not. Local gastrointestinal symptoms, such as nausea and constipation, are common with verapamil. None of the calcium channel blocking drugs have been reported to adversely affect lipid or protein metabolism. However, nifedipine, verapamil, and diltiazem in high doses may inhibit liberation of insulin. The significance of this finding needs to be explored further in hypertensive diabetics. Serum digoxin levels have been shown to increase after administration of verapamil and nifedipine, but there is no evidence that this change has any clinical relevance.(ABSTRACT TRUNCATED AT 250 WORDS)
Hypertension 1988 Mar
PMID:Side effects of calcium channel blockers. 328 Apr 92

Survival after closed-chest ablation of His bundle with DC shock for supraventricular arrhythmias was analyzed for a 10-year period (May 1982-December 1992) with 317 consecutive patients (167 males, 150 females; mean age 66 years; range 33-93 years). Of these, 54 patients died (17.3%) and 5 were lost to follow-up. The mean age at ablation was 70.3 +/- 8.3 years with a range of 49-93 years. Of those who died, the mean survival was 30.5 +/- 28.6 months with a range of 36 hours to 120 months; the diagnosis of heart disease was: hypertension (n = 14), cardiomyopathy (n = 8), ischemic (n = 7), valvular (n = 6), cor pulmonale (n = 3), valvular and ischemic (n = 2), hypertension and ischemic (n = 1), miscellaneous (n = 3), and none (n = 10). Of the patients who died after ablation, the arrhythmias at the time of the ablation were atrial fibrillation (AF; n = 33), sick sinus syndrome (n = 5), atrial flutter (AFL; n = 4), paroxysmal AV junctional tachycardia (PAVJT; n = 4), AF + AFL (n = 4), atrial tachycardia (n = 2), PAVJT + AFL (n = 1), and AF +AFL + atrial tachycardia (n = 1). Death was sudden in 13 patients (25%), due to heart failure in 10 (19.2%), myocardial infarction in 4 (7.7%), stroke in 4 (7.7%), aortic vascular accident in 3 (5.8%), miscellaneous in 18 (34.6%), and undetermined in 2.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Long-term survival after closed-chest His-bundle ablation with DC shock for supraventricular arrhythmias: a 10-year experience with 317 consecutive patients. 784 34

In a 20-year-old female patient with a brain stem glioma in the medulla oblongata in association with paraplegia and respiratory paralysis, bradyarrhythmias such as sinus bradycardia and sinus arrest repeated sporadically and transiently, but soon subsided as radiotherapy was being delivered to the glioma in the medulla oblongata. The bradyarrhythmias were differentiated from sick sinus syndrome in their sporadic and transient character. The patient responded normally to atropine, isoproterenol, and phenylephrine. Parasympathetic nerve reflexes induced by Aschner's, Czermak's, and Valsalva's maneuvers and sympathetic nerve reflex induced by change of body position were within normal limits. Although EKG abnormalities associated with diseases of the central nervous system are frequently due to intracranial hypertension and/or irritation of the hypothalamus, the bradyarrhythmias in this patient were possibly due to vagus stimulation caused by the glioma in the medulla.
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PMID:[A case of sporadic and transient bradyarrhythmias in a patient with a glioma in the medulla oblongata]. 835 39

Beta blockers in patients with sick sinus syndrome (SSS) may prevent supraventricular arrhythmias, systemic hypertension and myocardial ischemia, but may cause excessive depression of sinus node function. In 8 patients with SSS and a permanent pacemaker, the effect of chronic oral pindolol on sinus rate and pacing frequency was compared with that of propranolol in a double-blind crossover trial. In all patients the pacemaker was programmed to a rate of < or = 50 beats/min. Holter monitors, obtained at baseline and on each drug, were used to calculate peak ambulatory sinus rate, number of paced beats per day, maximal number of paced beats per hour, and percentage of hours with paced beats. The peak sinus rate with pindolol therapy was 24% higher than with propranolol (p = 0.001). During pindolol therapy, the number of paced beats per day and maximal paced beats per hour were reduced 54% (p = 0.04) and 61% (p = 0.02), respectively, compared with propranolol. Patients with SSS who require beta-blocker therapy for tachycardia, systemic hypertension or angina pectoris may have less bradycardia when treated with pindolol rather than propranolol. Beta blockers like pindolol, which cause less sinus node depression, may obviate the need for prophylactic permanent pacemakers in patients with SSS, and may help to prevent chronotropic incompetence and pacemaker syndrome in patients already treated with a VVI device.
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PMID:Comparison of effects of propranolol versus pindolol on sinus rate and pacing frequency in sick sinus syndrome. 842 Feb 36

A multicenter, retrospective study was undertaken to determine the prevalence of and risk factors for thromboembolism and efficacy of therapy in patients with atrial fibrillation. The primary prevention group consisted of 1,819 Japanese patients (mean age 64 years). During the mean follow-up period of 4.6 years. 158 patients developed cerebral thromboembolism or peripheral embolism (1.9%/year). The annual rate of thromboembolic complications was 0.9% for patients without underlying heart disease which was significantly lower compared with that for patients with underlying heart disease (p < 0.001). The annual rate was 1.4% among patients treated with aspirin (alone and in combination with other drugs except for warfarin), 1.4% with warfarin (alone and in combination with other drugs) and 1.1% with ticlopidine. The risk was lower for patients receiving these drugs (2.2%/year, p < 0.001). Among 801 patients not receiving treatment for thromboembolism, the annual rate was 0.9% for patients without underlying heart disease, which was significantly lower compared with patients with underlying heart diseases (e.g., 2.5% for ischemic heart disease and 2.1% for mitral valve disease, p < 0.001). Multivariate analysis using quantification method II revealed hypertension, sick sinus syndrome and left ventricular dysfunction (> or = NYHA class II) as risk factors for embolism. Although limited due to its retrospective nature, the present study suggests that the risk for embolism seems low in patients with atrial fibrillation but is not associated with underlying heart diseases or other risk factors, and antiplatelet treatment seems beneficial for these patients.
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PMID:[Atrial fibrillation and thromboembolism: a multicenter cooperative study. Research Group for Antiarrhythmic Drug Therapy]. 959 72

Whilst there are recognised ethnic differences in cardiovascular disease, with a higher prevalence of hypertension and complications such as stroke amongst black/Afro-Caribbean populations, and ischaemic heart disease being more prevalent amongst Indo-Asians, the literature describing the clinical epidemiology of atrial fibrillation (AF) in non-caucasian groups is scarce. To survey the clinical features and management amongst Indo-Asian patients with known AF, we studied patients from six general practices in the west of Birmingham. The six general practices had a combined practice population of 25051, from which, the Indo-Asian population was 14670. A total of 12 Indo-Asian patients (six male, six female; mean age, 67 years; range, 42 to 95 years) with known AF were identified, suggesting a prevalence of AF in Indo-Asians aged >50 years of 0.6%. Six patients had chronic AF, two had recent onset (defined as onset <six months) and four had paroxysmal AF. Five patients had a history of ischaemic heart disease, three had hypertension, seven had heart failure, two had alcohol excess, four had mitral valve disease, and one patient with paroxysmal AF had sick sinus syndrome. None could be classified as having lone AF. Only four patients were anticoagulated, but, of the remaining eight, who were not taking warfarin, six were taking aspirin. None of the patients had contraindications to warfarin, but one of the patients who was taking aspirin had poor compliance to warfarin. In this survey of a general practice Indo-Asian population of approximately 14670, we found 12 patients with known AF. More information on the clinical epidemiology of AF in non-caucasian groups is still needed and urgently required, in view of the public health implications of this common cardiac arrhythmia.
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PMID:Atrial fibrillation amongst the Indo-Asian general practice population. The West Birmingham Atrial Fibrillation Project. 970 15

An 86-year-old man had a history of hypertension and had been treated with calcium antagonist but no medications that could reduce heart rate. As a 12-lead electrocardiogram showed sinus bradycardia, complete right bundle branch block and left anterior fascicular hemiblock on his first visit to our hospital on January 1998, he was admitted to our hospital for further examination and treatment. A 24-hour Holter electrocardiogram demonstrated a total number of 74,182 heartbeats per day with pauses (> 2.0 sec) of 187/day. Overdrive atrial pacing study and His bundle electrogram revealed a prolonged corrected sinus node recovery time (5.820msec at a stimulation rate of 130/min) and H-V conduction time (80msec) with normal A-H conduction time, respectively. We diagnosed these abnormalities as sick sinus syndrome (Rubenstein II). His activity of daily living score was 30 points by the Barthel index on the day of admission. Oral administration of orciprenaline sulfate (30 mg/day), a beta-adrenoceptor agonist, was initially chosen rather than implantation of a cardiac pacemaker to increase his heart rate since he did not have any symptoms due to bradycardia and he did not give us an informed consent for the implantation. Orciprenaline sulfate, however, failed to increase total heartbeats (73,079/day). Then, oral cilostazol (100 mg/day), a phosphodiesterase III inhibitor, was administered. After two weeks of the regimen total heart beats were increased (85,642/day) with no pauses. The increase in heart rate resulted in the improvement of his activity of daily living (Barthel index: 55 points). Cilostazol could be the first line medication for elderly patients with bradyarrhythmia in whom implantation of cardiac pacemaker is not absolutely indicated.
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PMID:[Cilostazol increased heart rate with improvement of activity of daily living in an elderly patient with sick sinus syndrome]. 1055 64

To study the effects and characteristics of radiofrequency current catheter ablation (RFCA) in treatment of elderly patients with supraventricular tachycardia (PSVT), fifty-three elderly patients and fifty non-elderly patients with PSVT were included in this study. RFCA were performed in both groups. The group of elderly patients included 26 patients with atrioventricular nodal reentrant tachycardia and 27 patients with atrioventricular reentrant tachycardia due to 29 atrioventricular accessory pathways (Aps). Twenty-one patients were accompanied with hypertension and coronary heart diseases and 5 sick sinus syndrome cases in the elderly group. All patients in both groups were treated successfully with RFCA. The procedure time of ablation of slow pathway in elderly group was shorter than that of the non-elderly group (P < 0.01). A mild symptom of arterial thrombosis was found in 2 cases of the elderly group after treatment and was cured with aspirin. These results suggest that PFCA is very effective and safe in the treatment of elderly patients with PSVT, especially for patients accompanied with sick sinus syndrome.
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PMID:[Characteristics of radiofrequency current catheter ablation in the treatment of elderly patients with supraventricular tachycardia]. 1118 6

Symptomatic bradyarrhythmia occurs most often in aged patients. Most of these patients have multiple coronary risk factors and present with angina-like symptoms. The coexistence of CAD not only has major effects on their prognosis but also influences the long-term care. This study was designed to evaluate the incidence of coexistent CAD in patients with symptomatic bradyarrhythmias and its relationship to conventional coronary risk factors in Chinese people. From May 1996 to April 1998, we prospectively studied all consecutive patients admitted to our institution for symptomatic bradyarrhythmias requiring permanent pacemaker implantation. Coronary angiographies were performed non-selectively at the same session of pacemaker implantation. Based on the presence or absence of CAD, patients were divided into two groups for analysis. Multivariate logistic regression analysis was performed to determine independent predictors of CAD including sex, age, diabetes mellitus (DM), hypertension, hypercholesterolemia, and smoking. The odds-ratio (OR) and 95% confidence interval (CI) were determined. A total of 113 patients [68 males and 45 females, mean age 70.4+/-8.2 years old (range 45-86)] were included in our study. The diagnosis was sick sinus syndrome in 69 patients (61%) and atrioventricular block in 44 patients (39%). The incidence of CAD based on coronary angiography was 20%. The nodal-related artery was seldom involved among patients with coexistent CAD and symptomatic bradyarrhythmias (9%), and most patients had significant stenosis over LAD (74%). The baseline characteristics and presenting symptoms were not different statistically between patients with or without CAD. Hypercholesterolemia (OR 6.6, 95% CI 2.0-22.2, p=0.002) and DM (OR 4.7, 95% CI 1.3-17.2, p=0.020) were the two most significant independent predictors of CAD. In our patients with symptomatic bradyarrhythmias requiring permanent cardiac pacing, the incidence of CAD was 20% as determined by coronary angiography (CAG). Hypercholesterolemia and DM were the two most significant independent predictors for CAD in these patients. The nodal artery was seldom involved in patients with coexistent CAD and symptomatic bradyarrhythmias.
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PMID:The incidence of coronary artery disease in patients with symptomatic bradyarrhythmias. 1169 78

In rats, an increase in heart rate by pacing is accompanied by progressive large-artery stiffening. Whether this is also the case in humans is unknown. We enrolled 20 patients who were chronically implanted with a pacemaker because of atrioventricular block or sick sinus syndrome. Arterial distensibility was measured by an echo-tracking device. In 10 patients, the evaluation was performed on the radial artery by using continuous finger blood pressure measurements, whereas in the remaining 10 patients, the common carotid artery was studied with a semiautomatic measure of brachial artery blood pressure. Diastolic diameter, systodiastolic diameter change, and distensibility were obtained at baseline (heart rate 63+/-2 beats/min) and after atrial and ventricular sequential pacing at a heart rate of 90 and 110 beats/min. At baseline, the diameter was 7.8+/-0.3 mm in the carotid artery and 2.4+/-0.1 mm in the radial artery; the respective systodiastolic diameter change values were 375.4+/-31.0 and 55.9+/-9.0 (microm) and the distensibility values were 1.4+/-0.1 and 0.7+/-0.1 (1/mm Hg 10-3). Blood pressure and diameter were not significantly modified by increasing heart rate, which markedly modified systodiastolic diameter change and distensibility. In the radial artery, distensibility was reduced by 47% (P<0.05) at a heart rate of 90 beats/min with no further reduction at 110 beats/min. In the carotid artery, distensibility was reduced by 20% at a heart rate of 90 beats/min (P<0.05) with a further reduction at 110 beats/min (45%, P<0.05). These data provide the first evidence in humans that acute increases in heart rate markedly affect arterial distensibility and that this occurs in both large- and middle-size muscle arteries within the range of "normal" heart rate values.
Hypertension 2003 Sep
PMID:Effects of heart rate changes on arterial distensibility in humans. 1474 26


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