Clinical relevance of nighttime blood pressure and of daytime blood pressure variability.

BACKGROUND: The purpose of this study was to assess whether hypertensive target organ damage is related to average nighttime blood pressure (BP) and to BP variability. METHODS: Sixty-seven normotensive subjects and 171 borderline, 309 mild, 140 moderate, and 41 severe hypertensive patients were studied with noninvasive ambulatory BP monitoring. Each subject was assigned a target organ damage score of 0 to 5 on the basis of funduscopic changes and degree of left ventricular hypertrophy calculated from electrocardiogram and chest roentgenogram. RESULTS: When the 728 subjects were subdivided into five classes of increasing daytime BP, in each class a significantly higher degree of target organ damage was present in the subjects with higher nighttime diastolic BP. A similar, although nonsignificant, trend was observed in the subjects with higher nighttime systolic BP. In particular, higher nighttime BP levels were accompanied by a more severe degree of left ventricular hypertrophy. As for variability, subjects with higher daytime systolic BP SD, but not with higher daytime diastolic SD, displayed a more severe degree of target organ damage; this was accounted for by a higher degree of retinal abnormalities. The association between target organ damage and systolic BP SD was present both in men and women, while that with nighttime BP was present only in men. No relationship was found between degree of cardiovascular complications and peaks of pressure. CONCLUSIONS: These results suggest that a reduced day-night BP difference and an increased daytime BP variability, evaluated as the SD, are associated with a higher degree of hypertensive cardiovascular complications. Whether this BP profile is the cause or the consequence of target organ damage remains to be established.

Usefulness of handgrip to improve ibutilide efficacy in organizing atrial electrical activity during atrial fibrillation.

We analyzed the effect of handgrip on atrial electrical activity during atrial fibrillation (AF) by recording right and left atrial activity in 15 patients with persistent AF under baseline conditions and after saline and ibutilide infusions. The handgrip test for 15 seconds, which was always associated with a significant increase in mean atrial cycle length, was recorded in both atria (right atrium: saline vs saline + handgrip 141 +/- 29 vs 171 +/- 24 ms, p <0.001; ibutilide vs ibutilide + handgrip: 197 +/- 43 vs 221 +/- 39 ms, p <0.005). Handgrip favorably modifies atrial electrophysiologic properties during AF.

Italian style brewed coffee: effect on serum cholesterol in young men.

BACKGROUND: Increases in blood lipids have been observed in humans when coffee is brewed by the boiling method. The purpose of this study was to evaluate if giving up Italian coffee might reduce blood cholesterol levels. METHODS: Eighty-four normolipidaemic young adult males, after a 3-week baseline (BL), were randomly assigned to three different regimens of coffee consumption: espresso (E), mocha (M), and no coffee, but tea (T). The average coffee consumption during intervention (I) was 3.1 +/- 1.2 and 2.8 +/- 1.1 cups per day for espresso and mocha group respectively (espresso: 25-35 ml/cup; mocha: 40-50 ml/cup). Total cholesterol, HDL-cholesterol, LDL-cholesterol and triglycerides were measured eight times during the study. Dietary pattern, alcohol consumption, smoking habits, drug use, and anthropometric data were also recorded. RESULTS: The changes observed in serum cholesterol concentration between baseline and intervention were not statistically different in all groups. The changes were 0.0 mmol/l (T), +0.01 mmol/l (E) and +0.05 mmol/l (M) for total serum cholesterol; 0 mmol/l (T), -0.02 mmol/l (E) and -0. 03 mmol/l (M) for HDL-C; -0.13 mmol/l (T), +0.02 mmol/l (E) and -0. 05 mmol/l (M) for LDL-C. Serum triglycerides showed a significant increase during intervention (P < 0.01 by ANOVA) in all groups with a change of 0.18 mmol/l, 0.18 mmol/l and 0.22 mmol/l, for tea, espresso and mocha group respectively. CONCLUSIONS: The results indicate that coffee brewed in the Italian way does not alter blood levels of total cholesterol, HDL-cholesterol and LDL-cholesterol, since no significant differences were observed in these blood parameters after a 6-week break from coffee consumption.

Radiofrequency catheter ablation of atrio-ventricular accessory pathways.

Radiofrequency catheter ablation of accessory pathways may represent the treatment of choice for patients with symptomatic atrio-ventricular reentrant tachycardia or atrial fibrillation and a high ventricular response through the accessory pathways with short antegrade refractory period. Moreover, catheter ablation has contributed towards understanding anatomical and electrophysiological characteristics of accessory pathways. As far as anatomical characteristics accessory pathways may be classified into fibers with proximal insertion in right or left atrium and fibers with proximal insertion in the atrio-ventricular nodal junction. As far as electrophysiological properties are concerned, accessory pathways may be differentiated into non-decremental and decremental. In non-decremental by-pass tracts (the so-called Kent bundles) the impulse can be conducted antegradely, retrogradely and in both directions. Decremental accessory pathways generally show only antegrade conduction properties (the so-called Mahaim fibers) and can be classified in long and short pathways; in particular, catheter ablation has given considerable evidence that the vast majority (but not all) of them has a proximal insertion on the tricuspid anulus (atrio-ventricular pathways) or on the atrio-ventricular node (nodo-ventricular pathways). Decremental accessory pathways with only retrograde conduction properties are involved in the so called "Permanent Junctional Reciprocating Reentrant Tachycardia".

Ambulatory blood pressure monitoring in the assessment of antihypertensive treatment: 24-h blood pressure control with lacidipine once a day.

Ambulatory blood pressure monitoring gives a more representative blood pressure profile than office blood pressure measurements and is free of any placebo effect. It is therefore useful for studying the effect of antihypertensive agents. Although ambulatory blood pressure is less variable than office blood pressure, spontaneous fluctuations have been found in whole-day blood pressure when repeated measurements are taken. In the multicentre Triveneto Study, the mean difference between 24-h blood pressure recordings taken 3 months apart in 85 mild hypertensives was -0.1/-0.7 mmHg and the coefficient of repeatability (2 s.d.) was 17.3/12.6 mmHg. The corresponding values for office blood pressure were -8.7/-2.0 and 29.8/16.5 mmHg, respectively. This reduction in inter-measurement variability with ambulatory blood pressure monitoring makes it possible to reduce the sample size required to prove the effect of an antihypertensive agent in pharmacological trials. However, in the individual subject, the results of ambulatory blood pressure monitoring should be considered with caution, as 24-h blood pressure averages and profiles are subject to a degree of variability. This technique was used in 21 mild-to-moderate hypertensives to test the antihypertensive effect of lacidipine given once a day (4-6 mg) versus placebo. The drug proved effective throughout the day and night, showing a 24-h effect on blood pressure without reflex tachycardia or other intolerable side effects.

Automatic activity of a decremental long atrioventricular accessory pathway: an unusual feature.

The electrophysiological properties of decremental atrioventricular and atriofascicular pathways are not completely understood. We report the case of a patient with fast reentrant tachycardia due to a decremental long atrioventricular pathway, who showed a slow automatic tachycardia arising from the same pathway that was successfully eliminated by radiofrequency catheter ablation.

[Effect of high and low altitude exposure on the blood pressure response to physical exercise]. / Effetto dell'esposizione alle alte e basse quote sulla risposta pressoria all'esercizio fisico.

Altitude exposure is known to cause an increase in adrenergic activity, blood pressure (BP) and heart rate (HR) in resting conditions. Much less is known on the effects of the hypoxic environment on the BP and HR response to physical exercise. Five physically trained young normotensive subjects underwent a 1-hour long bicycle ergometric test to exhaustion at sea level and after 24 hours of low (1322 m) and high (3322 m) altitude exposure. HR, BP and Hb oxygen (HbO2) saturation were measured throughout the test and the recovery period. The values obtained at 60, 70, 80, 90 and 100% maximum HR were calculated. Resting BP increased by 17.9/20.9 mmHg at 3322 m (p = 0.062/0.012) and by 10.0/12.8 mmHg at 1322 m (NS). However, the BP difference present at rest gradually flattened throughout effort and at peak exercise similar BP values were obtained during the 3 tests. HbO2 saturation was lower at 3322 m compared to the other 2 settings (91.5% vs 96.7% at sea level; p less than 0.0001) and this difference progressively and remarkably increased throughout the ergometric test. At 3322 m a lower workload was reached (189 +/- 39.4 vs 240 +/- 54.8 W; p less than 0.05). In agreement with previous results these data show that exposure to both high and low altitude causes an increase in resting BP and HR; however, during strenuous exercise maximum BP and HR do not exceed the levels attained at sea level, probably on account of the lower workload that may be reached in the hypoxic environment.

[Radiofrequency transcatheter ablation of a bidirectional decremental accessory atrioventricular pathway in the coronary sinus]. / Ablazione transcatetere mediante radiofrequenza di via accessoria atrioventricolare decrementale bidirezionale in seno coronarico.

We report the case of a 63-year-old patient who underwent radiofrequency catheter ablation of an atrioventricular accessory pathway with bidirectional decremental conduction properties. The successful ablation site was the distal end of a wedge-shaped dilation of the first tract of the coronary sinus. Atrioventricular accessory pathways with anterograde decremental conduction properties was thought to belong to fibers with Mahaim type electrophysiological properties. They rarely show decremental retrograde conduction properties. Most Mahaim type atrioventricular pathways are right-sided with atrial insertion points at various sites along the tricuspid ring. On the other hand, left-sided decrementally conducting accessory pathways are very rare. Mahaim type atrioventricular pathways were never found in the coronary sinus. The bidirectional decremental conduction properties and in particular the anatomic site of the atrioventricular accessory pathway we describe in the present report are both very interesting findings.

[Wall elasticity of the ascending aorta in ischemic heart disease]. / Elasticità parietale dell'aorta ascendente nella cardiopatia ischemica.

M-mode echocardiography was used to examine in male subjects the physical properties of the ascending aorta, 3 cm above the valvular plane. Subjects were divided into three groups based on age, lifestyle and presence or absence of vascular disease: Group A (10 recruited military young men, age 20.87 +/- 0.834 years) in good health; Group B (14 senior competitive athletes, age 49.92 +/- 8.17 years); Group C (10 patients with effort-angina, age 53.1 +/- 11.18 years). We observed that: the inner diastolic diameter of the ascending aorta was different between Group A and B (p < 0.001) and between Group A and C (p < 0.001), and it increased with aging (r = 0.7) whereas no relationship to body surface was seen (r = 0.3); the elasticity-stiffness parameters (aortic wall distensibility, aortic wall stress, wall stiffness index, wall elasticity index and modulus) of major vessels in senior athletes (Group B), were not different (p > 0.05) from military young men (Group A), although they were significantly lower (p < 0.001) in Group C patients; wall elasticity was lower in Group C patients (versus both Group A and B). Altered compliance might be the consequence of vessel structural changes and may contribute to reduce blood flow to the coronary arteries. Our data suggest that sports activity has beneficial effects; physical characteristics of great vessels do not show age-related changes.

Successful ablation of atrioventricular nodal reentry tachycardia in a patient with persistent left superior vena cava.

We report the case of a patient with atrioventricular nodal reentry tachycardia associated with persistent left superior vena cava draining to a large coronary sinus. Successful ablation was performed at the level of the superior lip of the coronary sinus ostium.

[The normal limits of arterial pressure registered with portable methods: an approach to the problem]. / Limiti di normalità della pressione arteriosa registrata con metodiche portatili: un approccio al problema.

In the present paper the problem of the normalcy limits of whole-day ambulatory blood pressure has been faced by evaluating the difference between casual and ambulatory blood pressure in a population of 522 subjects with blood pressure values covering the whole blood pressure range. On the basis of the casual blood pressure levels, 60 subjects were normotensives, 110 borderline hypertensives, 214 mild, 103 moderate and 35 severe hypertensives. The differences between casual and median 24-hour blood pressure averaged 18.4/9.6 mmHg. The difference between casual and median day-time was 14.2/6.7 mmHg. This difference was independent from the ambulatory blood pressure values and unrelated to the sex or age of subjects. The upper normal limits of ambulatory blood pressure were established by subtracting the above differences from the normal limits established by the WHO for casual blood pressure (140/90 mmHg). For 24-hour blood pressure the upper limits were 121.6/80.4 mmHg and for day-time blood pressure these were 125.8/83.3 mmHg. Contrary to previous studies conducted on normotensive populations with this approach the selection of patients based on casual blood pressure is avoided and the WHO normalcy limits are taken into account.

[Clinical significance of nocturnal blood pressure and blood pressure variability: analysis of 522 cases]. / Significato clinico della pressione notturna e della variabilità pressoria: analisi di 522 casi.

Purpose of the study was to investigate whether and to what extent blood pressure variability and average night-time blood pressure are related to cardiovascular complications in hypertension. To this aim 60 normotensive and 462 hypertensive subjects were studied by means of non-invasive 24 hour blood pressure monitoring, using either the Avionics, or the ICR Spacelabs, or the Takeda system. Each subject was attributed a target organ damage score on the basis of 12-lead electrocardiogram, chest X-ray and fundoscopy, starting from 0 (no damage) up to 5 (maximum degree of damage). The 522 subjects were subsequently subdivided into 5 classes of increasing average daytime diastolic blood pressure. In each class a higher degree of cardiovascular complications was present in the subjects with the higher blood pressure variability and the higher average night-time blood pressure. From these results it may be inferred that both blood pressure variability and night-time blood pressure are related to the degree of target organ damage in hypertension. This stresses the importance of recording blood pressure throughout the 24 hours.