Management of hypertension in older persons

Antihypertensive therapy has been shown to reduce morbidity and mortality in older patients with elevated systolic or diastolic blood pressures. This benefit appears to persist in patients older than 80 years, but less than one third of older patients have adequate blood pressure control. Systolic blood pressure is the most important predictor of cardiovascular disease. Blood pressure measurement in older persons should include an evaluation for orthostatic hypotension. Low-dose thiazide diuretics remain first-line therapy for older patients. Beta blockers, angiotensin-converting enzyme inhibitors, angiotensin-receptor blockers, and calcium channel blockers are second-line medications that should be selected based on comorbidities and risk factors.     

Tilt table testing,methodology and practical insights for the clinic

Tilt table testing (TTT) has been used for decades to study short-term blood pressure (BP) and heart rate regulation during orthostatic challenges. TTT provokes vasovagal reflex in many syncope patients as a background of widespread use. Despite the availability of evidence-based practice syncope guidelines, proper application and interpretation of TTT in the day-to-day care of syncope patients remain challenging. In this review, we offer practical information on what is needed to perform TTT, how results should be interpreted including the Vasovagal Syncope International Study classification, why syncope induction on TTT is necessary in patients with unexplained syncope and on indications for TTT in syncope patient care. The minimum requirements to perform TTT are a tilt table with an appropriate tilt-down time, a continuous beat-to-beat BP monitor with at least three electrocardiogram leads and trained staff. We emphasize that TTT remains a valuable asset that adds to history building but cannot replace it, and highlight the importance of recognition when TTT is abnormal even without syncope. Acknowledgement by the patient/eyewitness of the reproducibility of the induced attack is mandatory in concluding a diagnosis. TTT may be indicated when the initial syncope evaluation does not yield a certain, highly likely, or possible diagnosis, but raises clinical suspicion of (1) reflex syncope, (2) orthostatic hypotension (OH), (3) postural orthostatic tachycardia syndrome or (4) psychogenic pseudosyncope. A therapeutic indication for TTT in the patient with a certain, highly likely or possible diagnosis of reflex syncope, may be to educate patients on prodromes. In patients with reflex syncope with OH TTT can be therapeutic to recognize hypotensive symptoms causing near-syncope to perform physical countermanoeuvres for syncope prevention (biofeedback). Detection of hypotensive susceptibility requiring therapy is of special value.     

Effects of calcium channel blockers on the endothelial release of von Willebrand factor after exercise in healthy subjects

Von Willebrand factor (vWF) is known to play a relevant role in the development of atherosclerotic lesions by promoting platelet adhesion to injured endothelial cells. An increase in cytosolic calcium has been shown to be associated with the in vitro release of vWF from endothelial cells. The aim of our investigation was to examine the effect of some calcium channel blockers on the release of vWF antigen (vWF:Ag) induced by exercise in two groups of eight healthy subjects during a randomized crossover study between placebo and calcium channel blockers. Placebo and verapamil (80 mg) or nicardipine (10 mg) were given orally at an interval of 2 weeks three times on the day before and once on the morning of the study day. Measurements of plasma vWF:Ag were made at rest and after a progressive maximal exercise on a cycloergometer. A significant increase in absolute values of vWF:Ag was observed after exercise in the subjects given a placebo in both verapamil (0.397 +/- 0.074 U/ml) and nicardipine (0.327 +/- 0.036 U/ml) groups, p less than 0.05. With use of verapamil the rise in vWF:Ag was blunted and not significant (0.123 +/- 0.081 U/ml) whereas a larger increase in vWF:Ag was found in the subjects given nicardipine in comparison with placebo (0.593 +/- 120 U/ml; p less than 0.05). No correlations were observed between exercise-induced changes in systolic or diastolic blood pressure, heart rate, blood lactate level, or pH and vWF:Ag changes in the subjects given a placebo or in those given calcium channel blockers.(ABSTRACT TRUNCATED AT 250 WORDS)     

Efficacy and Safety of Nifedipine Coat-Core versus Amlodipine in Patients With Mild to Moderate Essential Hypertension: Comparison of 24-Hour Mean Ambulatory Diastolic Blood Pressure

BACKGROUND: Calcium channel blockers have been successfully used for the treatment of hypertension. In this study, the antihypertensive efficacy and safety of the dihydropyridine calcium channel blockers nifedipine coat-core 30 mg and amlodipine 5 mg were evaluated. METHODS: This multicenter, double-blind, prospective, randomized, parallel-arm study compared once daily administration of nifedipine coat-core 30 mg with once daily amlodipine 5 mg in subjects with mild-to-moderate essential hypertension. A 4-week placebo run-in period was followed by an 8-week active treatment period. Blood pressure reduction was measured by ambulatory blood pressure monitoring and casual office blood pressure measured by mercury sphygmomanometer. RESULTS: Nifedipine coat-core and amlodipine produced equivalent reductions in mean diastolic blood pressure, as determined by 24-hour ambulatory blood pressure monitoring. Mean reduction in diastolic blood pressure was 5.4 mmHg and 5.8 mmHg for nifedipine coat-core and amlodipine, respectively. Both drugs were well tolerated and neither treatment resulted in a significant change in heart rate. CONCLUSIONS: Nifedipine coat-core 30 mg once-daily is comparable to amlodipine 5 mg once-daily for blood pressure reduction.     

A systematic approach to managing hypertension and the metabolic syndrome in primary care

OBJECTIVES: Obesity is driving a high prevalence of hypertension and metabolic syndrome-related risk and disease. This report summarizes the impact of a standardized, evidence-based approach to managing high blood pressure and associated metabolic syndrome abnormalities that was developed and implemented by one Clinical Hypertension Specialist. METHODS: Longitudinal data on blood pressure, low-density lipoprotein cholesterol (LDL-C), hemoglobin A1c (HbA1c), cardiovascular and renal comorbidities, and treatment medications were obtained on all 817 hypertensive patients seen from January 1, 2000 to June 30, 2003. RESULTS: The hypertensive patients were 72 +/- 11 (SD) years old, and more than 55% of them were high risk based on target organ damage, clinical cardiovascular disease, or diabetes mellitus. Blood pressure was < 140/90 mm Hg in 77% of all patients. Among the high-risk patients, mean blood pressure was 126 +/- 14/71 +/- 10 on 2.8 +/- 1.4 antihypertensive medications, with 88% on angiotensin converting enzyme inhibitors or angiotensin receptor blockers, 59% on diuretics, 49% on calcium channel blockers, and 36% on beta-blockers. Among dyslipidemic hypertensives, LDL-C was controlled to < 130 mg/dL in 84% (510/605) overall and to < 100 mg/dL in 70% of the high-risk group (299/427). Among diabetic hypertensives, the mean HbA1c was 6.8%, with 64% (155/242) less than 7%. New patients demonstrated improved blood pressure, LDL-C, and hemoglobin A1c control over time as the management algorithm was applied. CONCLUSIONS: A high prevalence of complicated hypertension was documented. Blood pressure, LDL-C, and HbA1c were controlled to goal in a high proportion of patients. The findings demonstrate that application of an evidence-based management algorithm can facilitate higher rates of cardiovascular risk factor control than are generally reported in primary care practices.     

Today's strategies for treating postoperative hypertension. Immediate evaluation and targeted treatment are required

Postoperative hypertension, though transient, requires immediate attention. Clinical variables include the patient's preoperative blood pressure, medications, and acute medical status; the surgical procedure performed; and the physiologic changes induced by surgery. Evaluate and treat any reversible causes of hypertension. Initiate drug therapy when organ failure or dysfunction is present or when the patient is at high risk for such complications. In choosing an agent, look for ease of administration, titratability of blood pressure response, rapid onset and cessation of action, and a low incidence of adverse effects. Options are nitrovasodilators, calcium channel blockers, ACE inhibitors, direct-acting vasodilators, adrenergic blockers, and neuromodulators (narcotics and anesthetics).     

两种钙拮抗药对高血压左心室肥厚患者心率变异的影响

目的：探讨高血压左心室肥厚（ＬＶＨ）患者的心率变异性（ＨＲＶ）以及分别受不同钙拮抗药的影响。方法：高血压左心室肥厚患者７０例随机分为维拉帕米、拉西地平组（各３５例）,分别早上顿服缓释维拉帕米２４０ｍｇ至４８０ｍｇ和拉西地平４ｍｇ至６ｍｇ,疗程１２周。治疗前后测ＵＣＧ、动态血压和动态心电图,观察降压和逆转ＬＶＨ的疗效,以及分析ＨＲＶ时域指标的改变情况。结果：治疗前患者的ＨＲＶ降低;两药降低血压的幅度     

Medical management of stable coronary artery disease

All patients with stable coronary artery disease require medical therapy to prevent disease progression and recurrent cardiovascular events. Three classes of medication are essential to therapy: lipid-lowering, antihypertensive, and antiplatelet agents. Lipid-lowering therapy is necessary to decrease low-density lipoprotein cholesterol to a target level of less than 100 mg per dL, and physicians should consider a goal of less than 70 mg per dL for very high-risk patients. Statins have demonstrated clear benefits in morbidity and mortality in the secondary prevention of coronary artery disease; other medications that can be used in addition to statins to lower cholesterol include ezetimibe, fibrates, and nicotinic acid. Blood pressure therapy for patients with coronary artery disease should start with beta blockers and angiotensin-converting enzyme inhibitors. If these medications are not tolerated, calcium channel blockers or angiotensin receptor blockers are acceptable alternatives. Aspirin is the first-line antiplatelet agent except in patients who have recently had a myocardial infarction or undergone stent placement, in which case clopidogrel is recommended. Anginal symptoms of coronary artery disease can be treated with beta blockers, calcium channel blockers, nitrates, or any combination of these. Familiarity with these medications and with the evidence supporting their use is essential to reducing morbidity and mortality in patients with coronary artery disease.     

Chronotherapeutics: a surge of ideas

Chronotherapeutics is advancing hypertension treatments beyond once-daily dosing by synchronizing the maximum levels of medication during times when cardiovascular risk is highest. It has long been established that patients are at higher risk for cardiovascular events-including myocardial infarction, stroke, and sudden death-in the early morning hours. Using novel oral delivery methods, chronotherapeutic medication synchronizes the delivery of blood pressure drug within the period of rates risk, significantly reducing both absolute blood pressure numbers and, especially important, the rate of blood pressure increase. These therapies have also shown the ability to maintain adequate blood pressure levels during the trough period. Several blood pressure medications now have chronotherapeutic formulations including the calcium channel blockers verapamil and diltiazem and the beta-blocker propranolol.     

NISOLDIPINE COAT-CORE AND HEART RATE RESPONSE DURING TREATMENT OF HYPERTENSION

Nisoldipine coat-core (nisoldipine CC), an extended-release once-daily formulation, is an effective treatment for mild-to-moderate hypertension, providing sustained blood pressure control over the 24-hour dosing interval. Nisoldipine CC is highly vascular selective. It causes neither reflex tachycardia nor symptomatic bradycardia; it lacks significant negative inotropy at therapeutic doses; and it does not affect circadian variation in blood pressure or heart rate. Data suggest that the lack of reflex sympathetic activation in response to the blood pressure-lowering effect of nisoldipine CC is due to the smooth onset of action of nisoldipine CC, causing resetting of the baroflex. The neutral heart rate profile of nisoldipine CC confers potential therapeutic advantages over several other calcium channel blockers, in particular, the short-acting agents, in the treatment of hypertension.     

EFFECTS OF CALCIUM ENTRY BLOCKERS ON BLOOD PRESSURE AND HEART RATE IN NEUROGENIC HYPERTENSIVE DOGS

The hypotensive and negative chronotropic effects of 5 calcium entry blockers (verapamil 200 micrograms/kg IV; diltiazem 300 micrograms/kg IV; nifedipine 5 micrograms/kg IV; nicardipine 50 micrograms/kg IV; and bepridil 5 mg/kg IV) were compared in control normotensive and acute neurogenic hypertensive anaesthetized dogs. Acute neurogenic hypertension was induced by sino-aortic denervation (SAD). In control normotensive dogs, all drugs (except bepridil) induced a slight and transient decrease in blood pressure. Nifedipine and nicardipine increased heart rate whereas the three other drugs remained ineffective. SAD caused a 2-2.5-fold increase in the hypotensive properties of the 5 drugs in dogs. Moreover, the duration of this induced hypotension was longer than in control normotensive animals. In SAD dogs, all calcium entry blockers significantly decreased heart rate. This study indicates that the direct cardiac inhibitory action of calcium channel blockers is modulated by baroreceptor activity in intact animals. The mechanism of the selective action of calcium entry blockers in hypertensive SAD in contrast to normotensive dogs is discussed.     

Holter monitoring for syncope: diagnostic yield in different patient groups and impact on device implantation

BACKGROUND: Holter monitoring is routinely used in patients referred for the evaluation of syncope, but its diagnostic value in different patient groups is unclear, as is its impact on device implantation (pacemaker or cardioverter-defibrillator). AIM: To determine the diagnostic yield of Holter monitoring in the routine evaluation of syncope, and its impact on subsequent device implantation. DESIGN: Retrospective record review. METHODS: We reviewed all Holter studies in patients referred with syncope between 2000 and 2005. Strict criteria were applied to determine whether a study was diagnostic. The diagnostic value of Holter monitoring (overall and in five subgroups: age, gender, structural heart disease, ejection fraction, medication) and its impact on the implantation of devices, were determined. RESULTS: Of 4877 Holter studies, 826 were performed in patients with syncope (age 72 +/- 15 years): 71 (8.6%) were considered to explain the syncope. Structural heart disease, ejection fraction and age were significant predictors of a diagnostic study (all p < 0.01), whereas gender and cardiac medication were not. A device was implanted in 33 patients (4.4%) whose initial Holter did not explain their syncope, after mean 7 months, whereas 45 patients (5.4%) received a pacemaker based on the Holter results (p = 0.32). DISCUSSION: The overall diagnostic yield of Holter monitoring in the evaluation of syncope was 8.6%, with dramatic differences between subgroups. Our data suggest that the impact of Holter monitoring on device implantation is generally overestimated.     

Vasovagal Syncope: Diagnostic Role of Head-Up Tilt Test in Patients with Positive Ocular Compression Test

We investigated the relative merits of the ocular compression test and the head-up tilt test to aid differentiation of syncope and seizures in young patients. Sixteen patients (10 males and 6 females) with a mean age of 14 ± 4.7 (SD) years (range 7–22 years) underwent graded head-up till (15°, 30°, and 45° for 2 minutes each, then 60° for 20 minutes) following positive ocular compression testing defined as precipitation of asystole for at least 3 seconds (mean 5 seconds ± 2 seconds, range 3–12 seconds). Each patient presented with recurrent unexplained loss of consciousness (mean number of episodes 30 ± 45, mean duration of illness 52 ± 40 months), and seven patients were receiving anticonvulsant medications, three of these had normal EEGs. Eleven patients (69%) developed vasovagal syncope during head-up tilt, reproducing their clinical episodes (systolic blood pressure decreased from 105 ± 10 mmHg to 84 ± 13 mmHg, diastolic blood pressure from 75 ± 9 to 22 ± 25 mmHg, and heart rate from 89 ± 13 beats/mm to 37 ± 20 beats/min). Asystole occurred in two patients during vasovagal syncope lasting 11 seconds in one and 16 seconds in the other, and, it was associated with myoclonic movements in both (convulsive syncope). Based on these findings, and given the perceived potential hazards of the ocular compression test, the head-up tilt test may be a safer procedure that adds useful information to the diagnostic evaluation of these patients.     

Calcium channel blockers as first line treatment for broad complex tachycardia with right bundle branch block: ingenuity or folly?

OBJECTIVE: To study the response of regular broad-complex tachycardia (BCT) demonstrating right bundle branch block (RBBB) to treatment in the Emergency department (ED). METHODS: Retrospective chart review of management of patients with BCT, RBBB without a history of ischaemic heart disease. A diagnosis of ventricular tachycardia (VT) was made if the ECG showed features such as atrioventricular dissociation, capture or fusion beats or if VT was demonstrated during electrophysiological studies (EPS). RESULTS: A total of 25 patients were eligible. Nineteen patients were given intravenous (IV) calcium channel blockers (either verapamil or diltiazem), as first line treatment. Of these, 18 converted to sinus rhythm and the other one patient subsequently converted with amiodarone. The remaining six patients were given IV adenosine (n=3), lignocaine (n=2) or amiodarone (n=1) as first line treatment but none of them were converted. Of these, four of them converted with IV calcium channel blockers eventually. Of the other two patients, who were both given lignocaine initially, one deteriorated haemodynamically with the use of verapamil and required synchronised cardioversion to convert. The other patient did not respond to amiodarone and synchronised cardioversion but was subsequently converted with verapamil. The difference between the success rate of calcium channel blockers and other anti-arrhythmics is statistically significant (P<0.01 by Fischer's exact method). Fourteen cases had diagnoses of VT, including the two patients given lignocaine. Five cases were found to have supraventricular tachycardia with aberrant conduction. Six cases did not have confirmed diagnoses. CONCLUSION: In patients presenting with BCT and RBBB but without underlying ischaemic heart disease, there is evidence to suggest that calcium channel blockers could effectively be used as the treatment of choice.     

Hypertension complicated with heart disease

Hypertension facilitates development and progression of cardiac diseases such as left ventricular hypertrophy (LVH), coronary artery disease (CAD), arrhythmia and heart failure. Strict blood pressure control over 24 hours is essential for the primary and secondary prevention of these cardiac diseases. Inhibitors of renin-angiotensin system(RASI) such as ACE inhibitors and angiotensin II receptor blockers(ARB) and long-acting calcium channel blockers(CCB) are effective in improving LVH. CCB and beta-blockers are preferentially chosen for CAD. RASI is expected to reduce the incidence of atrial fibrillation. RASI, beta-blockers and aldosterone blockers have been shown to improve the prognosis of heart failure patients. In addition, diuretics and long-acting CCB are used for the adequate control of body fluid volume and blood pressure.     

Managing hypertension using combination therapy

Combination therapy of hypertension with separate agents or a fixed-dose combination pill offers the potential to lower blood pressure more quickly, obtain target blood pressure, and decrease adverse effects. Antihypertensive agents from different classes may offset adverse reactions from each other, such as a diuretic decreasing edema occurring secondary to treatment with a calcium channel blocker. Most patients with hypertension require more than a single antihypertensive agent, particularly if they have comorbid conditions. Although the Joint National Committee guidelines recommend diuretic therapy as the initial pharmacologic agent for most patients with hypertension, the presence of "compelling indications" may prompt treatment with antihypertensive agents that demonstrate a particular benefit in primary or secondary prevention. Specific recommendations include treatment with angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, diuretics, beta blockers, or aldosterone antagonists for hypertensive patients with heart failure. For hypertensive patients with diabetes, recommended treatment includes diuretics, beta blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and/or calcium channel blockers. Recommended treatment for hypertensive patients with increased risk of coronary disease includes a diuretic, beta blockers, angiotensin-converting enzyme inhibitors, and/or calcium channel blocker. The Joint National Committee guidelines recommend beta blockers, angiotensin-converting enzyme inhibitors, and aldosterone antagonists for hypertensive patients who are postmyocardial infarction; angiotensin-converting enzyme inhibitors and angiotensin receptor blockers for hypertensive patients with chronic kidney disease; and diuretic and angiotensin-converting enzyme inhibitors for recurrent stroke prevention in patients with hypertension.     

Clinical Variables Associated with Mortality in Out-of-hospital Patients with Hemodynamically Significant Bradycardia

OBJECTIVES: To estimate mortality rates and identify clinical variables associated with mortality among patients with hemodynamically unstable bradycardia in an urban emergency medical services (EMS) system. METHODS: This was a retrospective study conducted in a large, urban EMS system. Adult non-cardiac arrest patients transported by advanced life support paramedics from March 1996 to February 1997 with a heart rate < or =60 beats/min and systolic blood pressure < or =90 mm Hg were included. Transcutaneous pacing was not available. Patients under age 18 years, pregnant, or presenting with vital signs absent were excluded from the study population. Multivariate analysis of the association of patient characteristics with 30-day mortality was conducted by using a Cox proportional hazards model. RESULTS: Of the 247 patients studied, 133 (53.9%) received a fluid bolus, 37 (15.0%) were treated with atropine, and 17 (6.9%) received dopamine. Fifty-one (20.7%) died in the 19-month follow-up period (15.6 per 100 person-years); 10.5% died on the same day, 15.8% within 30 days, and 17.8% within one year. Variables associated with 30-day mortality included wide QRS complex (adjusted risk ratio [RR] 2.6 [95% confidence interval (95% CI) = 1.3 to 5.2]), use of heart rate-lowering calcium channel blockers (adjusted RR 2.1 [95% CI = 1.0 to 4.7]), and paramedic assessment of lack of patient improvement over the course of the call (adjusted RR 0.2 [95% CI = 0.1 to 0.6]). CONCLUSIONS: Out-of-hospital patients with hemodynamically unstable bradycardia have a high mortality rate. A wide QRS complex and use of heart rate-lowering calcium channel blockers were associated with 30-day mortality.