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Although it has been recognized that enalapril lowers blood pressure by reducing the total peripheral vascular resistance, its direct effect on blood vessels is largely unknown. Little information is available about the influence of enalapril on the different vascular regions. Ten patients with moderate essential hypertension were treated with enalapril 20 mg daily in a double-blind, placebo controlled cross-over study for six weeks during each period. Blood pressure and heart rate were measured in supine, sitting and standing position. Venous capacity was derived from pressure volume curves plotted simultaneously at forearm and calf. Arterial blood flow at rest and during reactive hyperemia was measured at calf and finger by plethysmography. Enalapril increases venous capacity in upper and lower limbs in patients with moderate essential hypertension. Also, there is vasodilation of calf and finger arteries both at rest and during reactive hyperemia. Finger and calf arteries contribute to the decrease of the total peripheral vascular resistance during treatment with enalapril; thus, ACE inhibition is capable of correcting the increased peripheral resistance which often is the main cause of arterial hypertension.

Our previous studies have shown that blood pressure variability is not linked to activity of the adrenergic nervous system but that a small part of the variation is due to vagal nervous tone. The present work investigates whether myogenic activity of blood vessels could be responsible for the blood pressure variations. To test this hypothesis, variability was measured before and after administration of nifedipine, known to decrease spontaneous vascular contractions. In 17 patients with moderate essential hypertension, blood pressure was measured every 30 min for 12 h with a device recording Korotkoff's sounds on tape. Blood pressure variability was defined as the standard deviation of the mean of all readings. Placebo, nifedipine (20 mg b.i.d. in a slow-release formulation) alone and in combination with atenolol (50 mg b.i.d.), and atenolol alone were given double-blind for 3 weeks each. At the end of each period, a 12 h blood pressure profile was recorded. Systolic blood pressure significantly decreased with any of the drugs used; the combination of nifedipine and atenolol caused a greater decrease than that of any of the drugs alone. Diastolic blood pressure only decreased with the combination of nifedipine and atenolol. Nifedipine did not cause significant changes in systolic or diastolic variability; a small but nonsignificant decrease in diastolic variability was seen with atenolol and the combination of atenolol and nifedipine. The present data do not support the hypothesis that blood pressure variability is linked to myogenic vascular activity because no decrease in blood pressure variability was seen with nifedipine.

It has clinically well been recognized that the vectorcardiogram in younger patients often shows characteristics that are largely different from the figures obtained in general adult populations. Well documented information on VCG parameters in younger subjects is scarce; the present paper deals with a report on 194 white females and 63 white males, aged 18-25 years. Data were analyzed using the Pipberger program 3.6, and also statistically compared to the classical Pipberger standards. Some parameters (e.g. QRS duration) show different values typically in females, as well in our group of young females as in the reference Pipberger group; other measurements (e.g. Q/Rz amplitude ratio) are specifically deviated in the young population and a pronounced anterior displacement of QRS is regularly observed here. It appears remarkable that QRS amplitude in the young age groups is significantly higher than in the general Pipberger groups only when examined in the inferior direction. The 96% range limits found in this study resp. in young males, and in young females, for the QRS spatial maximal vector (3.08 resp. 2.61 mV) and for RX + RZ (3.22 resp. 2.45 mV) can be taken into account for considering LVH in youngsters.

Microbiological features, diagnostic investigations, treatment, and complication rate in 53 cases of infective endocarditis were reviewed in this study. Infection occurred both on prosthetic (47%) and native valves (38%), while in 15% of the cases no prior valvular disease was known. Streptococcal (38%) and staphylococcal (30%) infections were predominant. In 17% of the cases apparent negative blood cultures were obtained. The most frequent portal of entry was dental infection or manipulation (45%), however in 28% of the patients etiology remained obscure. Major clinical signs and symptoms included heart murmurs (96%), fever (91%), dyspnoea (32%), and splenomegaly (30%). Echocardiography revealed vegetations in 78%, aortic and mitral valve being nearly equally affected. All patients were medically treated and 53% received antibiotics prior to blood cultures. Associations of ampicillin or penicillin with an aminoglycoside (43%) and penicillinase-resistant antibiotics (30%) were most frequently administered. In 28% of the patients, it was necessary to insert a prosthetic (aortic or mitral) valve. During follow-up, heart failure (28%), embolization (11%), and infections (11%) were the major complications.

Six patients stabilized on long-term once daily oral digoxin were entered into a study to monitor the effect of adding a single dose of oral cicletanine (50 or 100 mg) on plasma digoxin levels. The study was performed over 2 days, a control day and a second involving the addition of the test drug to the patient's medication. No significant change in plasma digoxin concentration was found and the combined treatment was well tolerated in terms of clinical and laboratory parameters.

Cardiac dimensions and left ventricular function were investigated at rest with non-invasive methods in 14 professional road race cyclists and in 11 age-matched sedentary control subjects. The electrocardiographic findings were in agreement with previous studies in endurance athletes and the vectocardiographic data showed anterior displacement of the electrical forces. Echocardiographic dimensions at end-diastole showed higher values in the cyclists for left ventricular internal diameter, left ventricular posterior wall thickness, and interventricular septal thickness. Derived values for left ventricular volume and left ventricular mass were also much larger in the cyclists and there was excellent agreement between total heart volume measured with radiology and total measured by echocardiography. There was a significant correlation between maximal oxygen consumption and end-diastolic left ventricular diameter.

A patient with successful percutaneous transluminal coronary angioplasty of the left main coronary artery is described. Two days later coronary angiography was performed because of recurrence of angina pectoris. Spontaneous spasm at the angioplasty site was documented. This potentially lethal complication issues a severe warning against angioplasty of the left main trunk.

A prospective multicentre study has been set up to examine the following primary questions: (1) Is there a better correlation between blood pressure and mortality, morbidity or organ damage when blood pressure is measured by ambulatory recordings rather than by the usual office method? (2) Is there a difference in the rates of mortality, morbidity and organ damage when treatment is guided by ambulatory values instead of by office values? The aim is to study 2000 patients with primary hypertension, aged 35-70 years, for 5 years. Ambulatory recordings will be made every 6 months. Treatment will be based at random on either office or ambulatory blood pressure readings at each centre.

In these enzyme-linked immunosorbent assays for determination of autoantibodies (IgG, IgM) against collagen type I (ACA I), III (ACA III), and IV (ACA IV), we use commercially available antigen preparations. Inhibition curves showed limited cross-reactivity between these different collagen preparations, the major interference being observed after addition of collagen type III in the ACA I procedures. Imprecision (CVs) for high- and low-titer samples ranged between 1.5% and 7.9% (within-run) and 5.5% and 12.7% (between-run) for ACA I, between 2.2-8.7% and 4.5-10.7% for ACA III, and between 1.3-5.9% and 7.4-11.6% for ACA IV. Significantly increased humoral immune response against collagen types I and III (P less than 0.001) could be demonstrated during the first month of infective endocarditis. In contrast, only borderline increases, however constant, of autoimmune response against basement-membrane collagen (ACA IV) were noticed during 90 days of follow-up.

In 10 patients with a mean age of 76 +/- 8 years, a rate responsive pacemaker (Meta-MV, Telectronics) was implanted in the left pectoral site. An exercise test was performed in SSI ("adaptive") mode, allowing the device to measure the changes in thoracic impedance. The "slope number" at maximal exercise was chosen to program the pacemaker for a second exercise test in rate responsive mode. Direct measurements of respiratory rate and minute volume were correlated with the pacing rate. After 1 minute of exercise, pacing rate increased by 6% and it decreased smoothly after maximal exercise. The programmed maximal rate was reached at the maximum exercise level in six patients. During 24-hour Holter recording, the mean maximal pacing rate was 103 +/- 18 beats/min. For individual patients, a good correlation of pacing rate with respiratory rate (r = 0.757), oxygen consumption (r = 0.731), and minute volume (r = 0.800) was observed. The data from the entire group showed a highly significant correlation of changes in pacing rate and in respiratory parameters for different levels of exercise and recovery. In a subgroup of five patients, the slope numbers at maximal exercise were reproducible after 10 months. It was concluded that minute volume and its changes were recognized in a reliable way by the Meta-MV pacemaker.

A 72-years-old male patient is described who presented with relapsing, digital ulcers on both feet, accompanied by digital cyanosis ("purple toes"). All episodes occurred 5 months after starting coumarin treatment for chronic atrial fibrillation and low output failure. Massive mural thrombosis was discovered of the entire abdominal aorta. Because of the clinical picture, together with progressive renal failure and persistent eosinophilia, cholesterol embolization from an ulcerated atherosclerotic plaque within the mural thrombus was highly suspected. Besides the clinical presentation of our patient, the spectrum of cholesterol embolization is much wider. The role of coumarin therapy is still speculative. Numerous reports however, indicate a potential role in precipitating the syndrome. The only therapy available consists of removing the source whenever possible.

Early recurrence of symptoms after successful coronary angioplasty is usually due to restenosis of the angioplasty site. Multilesion progression of atherosclerosis in the presence of patent prior dilated segments has not, to our knowledge, been reported as a cause of early recurrent angina after successful double coronary angioplasty. As both new lesions were also successfully dilated, this case demonstrates that multivessel coronary angioplasty is a repeatedly effective and patient-friendly procedure to treat symptomatic coronary atherosclerosis with rapid and unpredictable rate of progression.

Blood pressure variability has been known in the cardiovascular clinic for a long time. The mechanisms of the variations are largely unknown; it was the aim of the present work to approach this question. In a first group of studies, the role of the adrenergic receptors was examined. The results have shown that the adrenergic system does not play an important role in this phenomenon as administration of beta and of alpha blocking agents is unable to diminish the amplitude of the blood pressure variations; this was confirmed by other studies showing no correlation between blood pressure variability and the response to sympathetic function tests. However, there was a positive correlation with the level of blood pressure. In a second part, the role of the cholinergic system was investigated; atropine was found to diminish, both in dogs as in men, the amplitude of blood pressure variability. No decrease of blood pressure variability was seen with calcium antagonists. Thus, blood pressure variability is depending on the level of blood pressure and cholinergic activity; since these mechanisms only explain part of blood pressure variability, further research will be needed to unravel this challenging question.

Unlabelled: The effects of oral sotalol were compared with 1000 and 1500 mg of procainamide in 23 patients with sustained ventricular tachycardia. The predictive value of an induction study after procainamide was assessed. The mean age of the study group was 62 +/- 12 years, and the mean ejection fraction was 32 +/- 16%. The cycle length (CL) of the induced tachycardia, the coupling interval (CI) of the first extrastimulus (in ms), and the number of noninducible (NI) patients are given in the table below. (table; see text) One patient developed torsades during the loading period of sotalol and is included in the number requiring cardioversion (DC). Important proarrhythmic effects (spontaneous occurrence of tachycardia) were seen twice after procainamide. Induction suppression by procainamide predicted success with sotalol (p = 0.0013)., Conclusion: Ventricular tachycardia seems to be less often inducible after oral sotalol than after procainamide. The success of procainamide during programmed electrical stimulation predicts the same for sotalol. If ventricular tachycardia remains inducible after oral sotalol, it is faster than after procainamide but slower than the baseline tachycardia. Both drugs slightly prolong refractoriness.

The role of ischaemia in the natural history of sustained monomorphic ventricular tachycardia not related to acute myocardial infarction is not well documented. We examined 38 patients (mean age 60 years, mean ejection fraction 33%) with programmed electric stimulation and thallium scintigraphy to study the presence of perfusion defects and to assess its prognostic significance. Reversible perfusion defects (RPD), alone or in combination, were seen in 17 patients (44.7%), persistent perfusion defects (PPD) in 31 (81.5%), and RPD and PRD combined existed in 14 patients (37%). Normal scintigrams were obtained in only four patients. Segmental analysis gave a mean 'infarction score' (number of PPDs on a total of 15 segments) of 4.2; the mean 'ischaemia' score (number of RPDs) was 1.2. Recurrence of tachycardia or sudden death was observed in 14 patients during a follow-up of 17 +/- 13 months. The predictive value (PV) of the presence of a RPD for recurrence was 63%, the PV of its absence was 82%; the predictive accuracy was 74% (P = 0.0069). This was as important as the data obtained with the drug studies (+PV 83%; -PV 86%; overall PV 83%, P = 0.002). The mean ischaemia score was 3.3 in the group with recurrence and 2 in the patients without recurrence. As pharmacological studies are only feasible in a subgroup with inducible tachycardia, thallium scintigraphy is of benefit to a larger group for predicting effective drug therapy and the risk of recurrence.

The present paper reviews our recent studies set up to define the role of sympathetic and vagal nervous influences on blood pressure variability. Blood pressure and its variability was measured in men by Arteriosonde or by Portometer (the latter recording 12 hours ambulatory blood pressure) and in the dog by intraarterial recordings. It was shown that sympathetic nerves do not influence variability as no change was seen with drugs acting on either beta (atenolol, metoprolol, propranolol) or alpha adrenergic receptors (prazosin, phentolamine, guanfacine). Also no correlation was found with plasma catecholamines or sympathetic function tests. By contrast, clear inhibition was demonstrated with atropine indicating an important role of vagal nerves on variability. However, in men, inhibition was not complete with atropine; thus, also other mechanisms play a role but these are, at present, largely unknown.

In this paper, the value of venous occlusion plethysmography in the differentiation between normal and abnormal is discussed. Data are obtained with an ECG triggered plethysmograph allowing an automatic and also a fast recording of the different parameters of the reactive hyperemia. A group of 74 proven "normal" limbs and of 93 proven "abnormal" limbs was studied. No difference in resting blood flow was seen; however, several parameters derived from reactive hyperemia were significantly different; curves obtained after arrest of the circulation during 3 minutes yielded the best results. Discriminant analysis showed that peak blood flow was the best individual performing parameter; using four variables of the reactive hyperemia curve, an overall performance of 84.9% was obtained with specificity of 93% and sensitivity of 76%. The place of plethysmography in the definition of vascular changes is discussed.

1. In 70 patients with untreated essential hypertension, blood pressure variability was correlated to plasma catecholamines and to the response of blood pressure and peripheral flow to cold pressure and handgrip tests. 2. Supine blood pressure was recorded every 5 min, during 3 h. Variability was defined as the standard deviation of the mean of the readings in that period. 3. Blood pressure variability is positively and significantly correlated to the level of pressure and to age. 4. No significant correlation could be found with plasma catecholamines and sympathetic function tests. 5. It is concluded that blood pressure variability is related to the level of pressure but not to activity of the sympathetic nerves.

During a consecutive period of 24 months, 244 patients with a major trauma were admitted to the Intensive Care Unit. From this pool of patients 60 consecutively were selected who did fulfill the selected criteria. We intended to determine within this studygroup the incidence, clinical features and outcome of patients with myocardial contusion (MC). We could conclude that no currently used diagnostic test may be seen as an accurate prediction of patients who still develop morbidity or mortality from cardiac contusion. Data from the literature suggest that at present only radionuclide angiography, direct hemodynamic measurement with construction of a Starling curve, and/or 2D-echocardiography may be useful in the identification of the patients at the greatest risk and predictive of the severity of the myocardial injury.

1. Changes in afferent activity in the aortic and sinus nerves with alterations of blood pressure were studied in anesthetized dogs. Mean aortic blood pressure was changed from 220 to 50 mmHg by using a pressurized reservoir connected to the abdominal aorta. 2. The stimulus--response curve (defined by measuring the mean impulse frequency at various pressures) from both nerves was S-shaped; the curve for the aortic nerve was shifted to the right of the sinus nerve curve. 3. In the dog, the aortic arch baroreceptors act predominantly as an anti-hypertensive mechanism; at lower pressures, the major control occurs through the sinus baroreflex.

The recent improvements in technology of cardiac pacing are often responsible for difficult electrocardiograms at follow-up (Gladstone et al., 1987). Therefore, it seems an advantage that most modern pacemakers include diagnostic software functions to explain the pacing behaviour (event markers, intracardiac electrograms...). In this case report an electrocardiogram, showing pacing dysfunction of a physiologic pacemaker with rate response is presented. It was possible to understand what was happening without electrograms, but confirmation of our interpretation of the pacing behaviour was only possible with telemetric data.

1. Dose-response curves of isoprenaline were constructed in nine hypertensive patients before and after either propranolol or metoprolol. 2. The decrease of diastolic blood pressure and increase of heart rate with isoprenaline were significantly more inhibited by propranolol than by metoprolol. 3. The increase in calf blood flow with isoprenaline was significantly more depressed after propranolol than after metoprolol. 4. The results suggest that the response of the vessels in the limbs to sympathetic stimulation is much less affected after metoprolol than after propranolol.

The diagnostic value of three noninvasive techniques was evaluated in a group of 100 "normal" and 100 "abnormal" limbs. The choice of segmental plethysmography, systolic pressure determination, and Doppler velocity curve was based on the fact that these methods are noninvasive, inexpensive, and atraumatic; they can easily be performed by paramedical personnel. There was a statistically significant difference between the ankle-to-arm systolic blood pressure ratio of normals and abnormals as measured by Doppler ultrasound with 0.96 as the dividing line, no false positives and only 11% false negatives were found. However, there was a large overlap for many parameters calculated from the velocity curve. The general morphological aspect of the velocity curve shows a better diagnostic performance than the calculated parameters of this curve: a monophasis curve had an 85% chance of being normal. The ankle segmental plethysmogram yielded only 5% false negatives, but 20% false positives; moreover, a biphasic curve has a 90% chance of being normal. Thus large-scale screening in clinical practice or in epidemiologic studies can best be done by Doppler pressure measurements; the velocity curve performs less satisfactorily. Segmental plethysmography is more sensitive, but it yields more false positive results.

In contrast to the systolic blood pressure at the posterior tibial artery, the evaluation of pressure at the digital artery of the foot before and after exercise in patients with peripheral arterial disease is not well known. Twenty three patients with peripheral vascular disease were examined. The systolic pressure was measured by means of an ultrasound velocity detector at the brachial and posterior tibial artery. Digital artery pressure was determined with photoplethysmography. Pressures were measured before and within 5 and 10 minutes after a treadmill test. Ankle and toe index was calculated. At rest the toe index is lower than the ankle index and after a treadmill test the decrease in toe index occurs in parallel to the ankle index.

Peripheral arterial occlusive disease has been described frequently as a disease affecting predominantly men. There is only a few information available concerning peripheral vascular disease in the female. Therefore, the aim of the present study was to examine risk factors in relation to localisation and symptoms of peripheral arterial occlusive disease in female patients. A retrospective study has been performed in 48 female patients (52-82 years with a mean age 69.5 years). Finally 45 patients were witheld because they had all a doppler examination and an oscillography of the lower limbs. The majority of the patients, namely 22 patients (49%) had combined ileofemoral and distal lesions. There were 15 patients (33%) who had isolated distal lesions, while only 8 patients (18%) had isolated ileofemoral vascular lesions. With respect to the symptoms the population could be divided in three groups: 16 patients (36%) were asymptomatic, 19 patients (42%) had intermittent claudication and 10 patients (22%) had rest pain and necrosis. Smoking was not the predominant risk factor in this group. Diabetes mellitus seemed to enhance distal vascular lesions, while arterial hypertension, obesity and lipids were predictive risk factors in peripheral vascular disease in the female. A high incidence of cardiovascular disease (31 patients, 69%) and cerebrovascular disease (13 patients, 29%) was concomitant.

The diagnostic value of different parameters derived from the Doppler velocity curve recorded at the ankle was analysed in a population of 432 subjects. To document the presence or absence of obliterative arterial diseases in the lower limbs, systolic blood pressure measurements were made and oscillography before and after exercise was recorded. A descending slope below 20.5 mm as recorded during 0.40 sec, appears as a sensitive indicator of occlusive arterial diseases of the lower extremities: 84% of the limbs were correctly classified showing with a high sensitivity of 91.8% but a lower specificity of 76%. By considering a combination of two parameters (descending slope and crest-time), the overall performance increases up to 88% and specificity becomes satisfactory (85%), while sensitivity is kept at 90%. Quantitative analysis of the Doppler velocity curve recorded at the ankle is feasible and is most helpful in discriminating normal and abnormal limbs both in daily clinical practice and in large scale studies.

During a decade (1975-1985) 15 patients have been treated for a primary cardiac tumor at the University Hospital of Ghent. Histological examination revealed both benign (n = 12) (myxoma, pseudomyxoma, myxoid degeneration) and malignant (n = 3) (angiosarcoma) tumors. Tumor diagnosis generally was made by echocardiographic and/or angiocardiographic examination of patients presenting with various constitutional and/or cardiac symptoms. In two patients however diagnosis became obvious by histological examination of the material removed during acute embolectomy. All tumors were surgically resected with the aid of extracorporeal circulation. Benign tumors have generally good prognoses, although rhythm or conduction disturbances, complete obstruction or embolization can entertain malignant consequences. Three of our patients died of such a complication. Therefore all cardiac tumors should be resected as soon as possible after diagnosis. One patient showed evidence of recurrence of the tumor. Malignant heart tumors have bad prognoses: all three of our patients died within two years.

In this paper a number of techniques are described that provide information concerning the functional disturbances caused by anatomic lesions within the vascular system in patients with intermittent claudication. These techniques are part of a currently growing entity that is called the "Vascular Laboratory". Main characteristics of these techniques are that they are painless, atraumatic and without any danger to the patient. Therefore, they can both be used for diagnosis as well as for follow-up of the patients. Moreover, many of them are useful for detecting stenotic lesions at an early stage of evolution. In any patient with intermittent claudication, the walking distance, oscillography at rest and after exercise and systolic blood pressure determination should be performed. Segmental plethysmography is extremely sensitive mainly when performed together with systolic blood pressure determination. Venous occlusion plethysmography has been significantly improved in recent years and is capable of providing direct information concerning the circulation through the diseased limb. There seems to be tremendous improvement in the techniques using ultrasound allowing presently construction of an anatomic picture of the vessels (Ultrasonic arteriography).

Twenty patients with intermittent claudication and having an ankle/arm blood pressure ratio less than or equal to 0.75 were randomized to receive ketanserin 40 mg b.i.d. or placebo for three months under double-blind conditions following a six-week run-in period. A placebo was administered for an additional six weeks at the end of the double-blind phase. Results indicated that ketanserin significantly increased (p less than 0.04) the pain-free walking distance by 36% versus a non-significant 10% rise with placebo. During the run-out period, this parameter remained significantly increased (p less than 0.04) with ketanserin. Changes in the total walking distance during the double-blind period were 15% and 11% for ketanserin and placebo, respectively, with a significant (p less than 0.05) increase to 30% occurring in the ketanserin group during the run-out phase. There was a decrease in the ankle/arm blood pressure ratio in the worst leg in both groups. The rise of systemic blood pressure after exercise was attenuated with ketanserin. Side-effects were reported in only one patient in the placebo group. These data indicate that ketanserin may be of value in patients suffering from intermittent claudication. Other studies are, however, warranted to determine whether this beneficial effect is general or restricted to a subgroup of patients.

Cardiovascular hemodynamics were studied noninvasively before, during and after hemodialysis with ultrafiltration in 18 patients on chronic hemodialysis. The cardiac output (CO) was determined by a continuous wave Doppler method. Overall, no major CO changes were seen (7.8 +/- 0.6 l/min post- versus 7.4 +/- 0.5 l/min pre-dialysis). Mean blood pressure rose slightly but significantly from 103 +/- 4 mmHg before to 113 +/- 3 mmHg after hemodialysis (p less than 0.01). Important interindividual differences in the intradialytic evolution of CO were observed. In patients with previous myocardial infarction or dilated cardiomyopathy (n = 12), CO rose significantly from 7.3 +/- 0.7 l/min before to 8.4 +/- 0.6 l/min after hemodialysis (p less than 0.05), while in patients without manifest myocardial disease (n = 6) CO decreased from 7.5 +/- 0.7 l/min to 6.6 +/- 0.9 l/min (NS). Comparison of the evolution of CO in both groups by variance analysis revealed a significant difference (p less than 0.01). It is concluded that, in response to hemodialysis with ultrafiltration, CO probably will increase in patients with myocardial infarction or congestive cardiomyopathy, but probably will decrease in patients without.

From the literature concerning the electrocardiological diagnosis of myocardial infarction, data are reviewed illustrating the role of the scalar orthogonal approach by the Frank system. Special attention is drawn to the Q/R ratio as a parameter. Criteria for the most frequent differential diagnoses are summarized in a practical way. The importance of the concepts sensitivity and specificity is stressed, while statistical methods for establishing the value of parameters are discussed. Results of multivariate analysis are indicated.

Although the historical debate between Pickering and Platt has never been settled, most scientists have felt that hypertension should not be defined as a disease state, qualitatively different from normotension with a sharp dividing line in between them. Still, in clinical practice, there is a need for well defined limits which one should initiate therapeutic actions that should not be taken below such a limit. In fact, in trying to escape to setting up a sharp limit, clinicians have tried to find a level above which benefits of decreasing blood pressure could outweigh the potential harm caused by the therapeutic interventions. However even in that way, finding such a limit is a most difficult enterprise; it has necessitated many large trials which certainly have not resolved yet all our questions. First, one should realize that blood pressure by itself is not a constant value; following blood pressure over a certain period shows its large variations from "normotensive" ranges to clearly "hypertensive" levels in the same individual. As soon as one is spoiled by this type of information, it becomes hardly conceivable to define someone's blood pressure without ambulatory recordings of some kind. This is also valid for finding the above mentioned limit of therapeutic benefit; an European International multicenter studied is being set up in this respect (HOME BP). Moreover, whatever the definition of blood pressure, its relationship to mortality, morbidity and organ damage, also, is not a constant one.(ABSTRACT TRUNCATED AT 250 WORDS)

It is not clear whether hemodynamic and other benefits from dual-chamber pacing also exist in elderly patients. We studied a group of 18 elderly patients (mean age 74 +/- 4 yrs) with exercise testing in DDD and VVI modes in a randomized way to compare the effects of these pacing modes on exercise capacity, atrial rate and exercise-induced arrhythmias. Patients were selected when complete heart block was present without clinical evidence of sinus node dysfunction. Significant differences were observed: atrial rate was lower during exercise in DDD-mode (p less than 0.01); exercise time and cumulative load increased (p less than 0.05); maximal oxygen uptake was improved (p less than 0.05). Some of these differences were less clear in a subgroup with replacement of a VVI-device by DDD-stimulation. No differences could be observed in severity of exercise-induced arrhythmias. No evidence of sinus node dysfunction was found during exercise. Reprogramming of atrial sensitivity was required in 3 patients, with reprogramming to DVI because of paroxysmal atrial fibrillation once. Two patients died within a mean follow-up period of 13 months. Sinus rhythm was present at the most recent evaluation in all patients, including the patient stimulated in the DVI mode. Physiologic stimulation is of value for elderly patients with an active life style and complete heart block. Reprogramming to another pacing mode is only seldom necessary.