Combined Diagnostic Yield of Tilt Table Test And Implantable Loop Recorder to Identify Patients Affected by Severe Clinical Presentation of Neurally-Mediated Reflex Syncope who Could Respond to Cardiac Pacing.

In this study we wanted to verify the diagnostic value of tilt table test (TTT) to predict the efficacy of cardiac pacing (PM) for preventing recurrences of neurally mediated reflex syncope (NMS) in patients with cardioinhibitory activity (CI) documented by implantable loop recorder (ILR). Among patients selected by ILR in the context of severe clinical presentation of NMS, we analysed those who underwent PM implantation. In this observational and retrospective study we wanted to verify the results of TTT in the groups of treated patients with and without recurrences. We analysed 24 patients treated using a PM (10 male and 14 female, mean age 70 years). During an average follow-up period of 35 months the recurrence of syncope occurred in 7 patients (29%). 17 patients (71%) had not recurrences. TTT was negative in 15 patients out of 17 without recurrences (88%). Among the 7 patients with recurrences TTT was positive in 4 patients (57%). In conclusion, in this selected group of patients, a positive response to TTT is more likely correlated with a higher frequency of recurrences of syncope, while a negative response seems to predict the success of the pacing therapy. Consequently, PM could be insufficient to prevent the recurrences in the group of patients with positive TTT.

Implantable Loop Recorder: Diagnostic Yield And Possible Therapeutic Effect In Patients With Neurally Mediated Reflex Syncope.

Through a retrospective study concerning the experience of our center in patients affected by Neurally Mediated reflex Syncope (NMS) we wanted to verify not only the diagnostic yield of the Implantable Loop Recorder (ILR) but its possible placebo therapeutic effect. In the context of patients affected by a severe clinical presentation of NMS identified through a careful clinical evaluation, we selected those who followed a diagnostic iter using the ILR. We analysed 84 patients (39 male and 45 female, mean age 71 years), during the period 2009-2013. 34 patients (40.5%) had no recurrences after a mean follow-up (FU) of 35 months, among these 17 concluded a FU of 4 years. 50 patients (59.5%) had recurrences and a specific diagnosis after an average period of 7 months. We found an important number of patients who showed a disappearance of syncope during an observation period of 2-3 and 4 years. At first glance this results could be explained considering the possible placebo therapeutic effect of ILR.

Genesis and acoustic quality of the physiological fourth heart sound.

The genesis of the fourth heart sound (S4) is commonly related to the rapid set in vibration of the left ventricular walls, resulting from the rapid inflow of the blood due to the atrial contraction (Nishimura et al., 1989). S4 can be recorded in normal young subjects as an expression of physiologic atrial dynamics but it is more common in pathologic conditions characterized by decreased ventricular distensibility (Tavel, 1978). Employing the spectral analysis of heart sounds (Longhini et al., 1979; Longhini et al., 1981; Aubert et al., 1984) we searched for the relationship between different components of the frequency spectrum of S4 and various echocardiographic parameters, with the aim of identifying the cardiac structures involved in its genesis (Longhini et al., 1989; Baracca et al., 1991).

The response of the ageing heart to regular physical exercise. An echo and Doppler study.

In upper middle age healthy subjects the functional cardiac reserve is known to be decreased (Port et al., 1980; Aubert et al., 1994). On the other hand regular physical exercise improves the cardiovascular function (Nishimura et al., 1980). The aim of this study was to establish whether regular physical exercise is associated with a significant change in the ageing process of the cardiovascular system.

Clinical value of the pitch of the third heart sound in ischemic heart disease.

The study investigates the genesis of the third heart sound (S3) in ischemic heart disease based on a mass-spring model. In such a system, the natural frequency of vibration, Fn, depends on the elastic constant, k, and the mass, m, according to the following relationship: Fn = 1/2 pi square root of k/m. To identify the cardiac structures representing k and m, the correlations between the energy of the S3 spectrum and the echocardiographic parameters were searched for. The results are consistent with a model in which k is represented by the thickness of the left ventricle and m by its blood content. The k/m ratio emerges as an important determining factor of the acoustic quality of S3, and yields information on the dysfunction of the left ventricle in ischemic heart disease.

Circadian rhythm of blood pressure and calcium entry blockade: a chronobiologic study with nitrendipine in essential hypertension.

In order to evaluate the chronobiologic effect of nitrendipine, 27 patients with mild-to-moderate arterial essential hypertension were studied. After randomized administration of 20 mg of nitrendipine and placebo, systolic and diastolic blood pressure (SBP and DBP, respectively) and heart rate (HR) were measured for 24 h using an automatic noninvasive device. The data of the time series were statistically analyzed by single and mean cosinor methods (obtaining mesor, amplitude, and acrophase) and by ANOVA and Student's paired t test. Nitrendipine significantly reduced the SBP and DBP mesors without affecting the HR mesor, and reduced the SBP and DBP amplitudes while increasing the HR amplitude. After placebo, group circadian rhythms were observed for SBP, DBP, and HR and maintained after nitrendipine. In conclusion, a single-dose administration of nitrendipine is effective in lowering blood pressure. The increased HR amplitude is probably due to a tachycardic reaction. The preservation of the SBP, DBP, and HR group circadian rhythms agrees with the lack of interference of the drug with the neurohormonal mechanisms.

Acute and chronic nitrendipine administration in essential hypertension: a chronobiologic study.

To evaluate the chronobiologic pattern of the hypotensive effect of nitrendipine, 10 patients with mild-to-moderate arterial hypertension were studied. They received a randomized single dose (20 mg) of nitrendipine and placebo, and 20 mg of nitrendipine daily for 2 months. Systolic and diastolic blood pressure (SBP and DBP, respectively) and heart rate (HR) were measured for 24 h using an automatic noninvasive device. The data were analyzed by single and mean cosinor methods and by ANOVA and Student's paired t test. Chronic administration of nitrendipine resulted in a more effective lowering of the SBP and DBP mesor, compared with placebo and acute administration, preserving the circadian rhythms. The preservation of the HR circadian rhythm agrees with the lack of interference of the drug with neurohormonal mechanisms.

The effect of captopril on peripheral hemodynamics in patients with essential hypertension: comparison between oral and sublingual administration.

A comparative study of the effects of oral and sublingual captopril on the hemodynamics of the peripheral musculocutaneous vasculature was carried out on ten patients with essential hypertension. Both routes of administration of captopril lead to lower blood pressure and decreased regional resistance, and to an increased arterial blood flow at rest. The first measurable effect and the peak effect on blood pressure and peripheral hemodynamics appear slightly earlier with sublingual administration. The data provided in this study support the usefulness of the sublingual route in clinical situations in which oral administration of captopril is not feasible.

Peripheral vascular circulation in trained athletes.

Modifications in the neurogenic control are important in cardiovascular adaptation to physical training. To examine the influence of such variations on arterial blood pressure, heart rate and limb blood flow the Authors have studied the reaction to cardiovascular stress tests of soccer players and sedentary controls. No difference was found in the blood flow response between athletes and sedentary subjects. However, the tests inducing sympathetic activation determined blood pressure response of different intensity, possibly related to the differences in the autonomic nervous system control.