Search results for "HEART RATE"
showing 10 items of 887 documents
Heart rate variability in sick sinus syndrome: does it have a diagnostic role?
2019
BACKGROUND: Hypothesis of our study was that the irregular rhythm of sick sinus syndrome (SSS) was characterized by an augmented HRV. Objective was to assess whether SSS patients had a typical HRV profile. METHODS: We screened all 1947 consecutive Holter ECGs performed in our Units of Vascular Medicine and Internal Medicine and Cardioangiology at the University of Palermo (Italy) from April 2010 to September 2014. Among these, we selected 30 patients with ECG criteria of SSS. They were compared to 30 patients without SSS matched for age, sex and comorbidities. RESULTS: The SSS group had a lower mean heart rate (HR) (P=0.003), and a longer mean NN max-min longer (P<0.0005) compared to con…
Impact of ''off-label'' use of ivabradine on exercise capacity, gas exchange, functional class, quality of life, and neurohormonal modulation in pati…
2010
Background: Epidemiologic studies indicate that elevated heart rate (HR) is an independent risk factor for mortality and morbidity in patients (pts) with chronic heart failure (CHF). Clinical trials with b-blockers suggest that HR reduction is an important mechanism of their benefit in pts with stable CHF. Pharmacologic inhibition of the If current now provides the opportunity of pure HR reduction. The purpose of this study was to evaluate the impact of ‘‘Off-Label’’ use of ivabradine on exercise capacity, gas exchange, functional class, quality of life, and neurohormonal modulation in pts with ischemic CHF. Methods: Between January 2008 and June 2008, a graded maximal exercise test with re…
Cardiac arrhythmias as correlated with the circadian rhythm of arterial pressure in hypertensive subjects with and without left ventricular hypertrop…
1990
To evaluate the relationship among supraventricular and ventricular arrhythmias with blood pressure and heart rate (HR) values, we studied 2 groups of 20 hypertensive men with (group I) and without (group II) left ventricular hypertrophy. Ambulatory electrocardiographic tracings were recorded continuously, together with ambulatory arterial pressure. Systolic (SBP) and diastolic (DBP) blood pressure values measured over 24 h showed no difference between the two groups, but we found greater variability in SBP in group I. The incidence of ventricular and supraventricular arrhythmias was significantly higher in patients of group I; moreover, we found a strong correlation between the incidence o…
Pavlovian conditioning of corticotropin-releasing factor-induced increase of blood pressure and corticosterone secretion in the rat
1992
Corticotropin-releasing factor (CRF) is clearly involved in the central regulation of the pituitary-adrenal axis and, moreover, of autonomic nervous system functions. Enhanced sympathetic activity with subsequent increases in blood pressure and heart rate and attenuation of the baroreceptor reflex results from the intracerebroventricular (i.c.v.) administration of CRF. Additionally, the peptide has a variety of potent effects on behavioural responses in animals similar to those observed after an experimentally evoked stress. It was therefore of obvious interest to examine whether CRF is a possible mediator of the learning processes associated with physiological stress reaction patterns. Thi…
Cardiac sympathetic activation and parasympathetic withdrawal during psychosocial stress exposure in 6‐month‐old infants
2020
Infant autonomic reactivity to stress is a potential predictor of later life health complications, but research has not sufficiently examined sympathetic activity, controlled for effects of physical activity and respiration, or studied associations among autonomic adjustments, cardiac activity, and affect in infants. We studied 278 infants during the repeated Still-Face Paradigm, a standardized stressor, while monitoring cardiac activity (ECG) and respiratory pattern (respiratory inductance plethysmography). Video ratings of physical activity and affect were also performed. Respiratory sinus arrhythmia (RSA) and T-wave amplitude (TWA) served as noninvasive indicators of cardiac parasympathe…
Assessment of heart rate variability (HRV) in subjects with type 2 diabetes mellitus with and without diabetic foot: correlations with endothelial dy…
2021
Abstract Background Some studies have suggested that patients with diabetes and foot complications have worse cardiovascular and cerebrovascular risk profiles, higher degrees of endothelial dysfunction and arterial stiffness and a higher inflammatory background than patients with diabetes without diabetic foot complications. Patients with diabetes mellitus have an alteration in the sympathovagal balance as assessed by means of heart rate variability (HRV) analysis, which is also related to the presence of endothelial dysfunction. Other studies suggest a possible role of inflammation coexisting with the alteration in the sympathovagal balance in favor of the atherosclerotic process in a mixe…
The effect of methacholine on noradrenaline release from the rabbit heart perfused with indometacin
1974
The experiments were undertaken in order to study the effect of inhibition of prostaglandin synthesis on the muscarinic inhibition of noradrenaline release evoked by sympathetic nerve stimulation. The right sympathetic nerves of the perfused rabbit heart were stimulated electrically. The noradrenaline output was enhanced after perfusion of the hearts with indometacin 3×10−5 M indicating blockade of the prostaglandin-mediated negative feedback control. Both in the presence and in the absence of indometacin methacholine 4×10−5 M decreased the noradrenaline output by a similar percentage. It is concluded that the muscarinic inhibition of noradrenaline release does not require the functional in…
Favorable clinical heart and bone effects of anti-thyroid drug therapy in endogenous subclinical hyperthyroidism
2007
Although subclinical hyperthyroidism (SCH) has been associated with increased risk of osteoporosis and cardiac arrhythmias, its treatment is still controversial. This study was designed as a prospective, randomized, intervention, control-study with a 1-year follow-up in order to investigate whether normalization of serum TSH in SCH using methimazole has favorable bone and heart clinical effects. Fourteen patients with endogenous SCH (not Graves' disease) were enrolled, 7 (5 women/2 men; group T) were treated with methimazole (2.5-7.5 mg/day), and 7 (5 women/2 men; group C) were followed without treatment; 10 healthy subjects were also included in the study as controls. Serum free-T3 (FT3), …
Ventilation and Heart Rate Response During Exercise in Normals: Relevance for Rate Variable Pacing
1993
The observation of a close relationship of heart rate to oxygen uptake (HR-VO2) and heart rate to minute ventilation (HR-VE) has been shown to be of particular value in rate variable pacing. However, the impact of anaerobic threshold (AT) for the HR-VO2 and HR-VE slope has been studied less. Twenty-three male and 16 female subjects, mean age 52 +/- 7 years, were selected in whom complete heart catherization and extensive noninvasive studies excluded major cardiopulmonary disease. Semisupine bicycle exercise testing with analysis of respiratory gas exchange was performed using a ramping work rate protocol with work increments of 20 watts/min. At the respiratory AT, determined by the V slope …
Sudden cardiac death while wearing a Holter monitor
1991
The Holter tapes of 61 patients (46 men, mean age +/- standard deviation 65 +/- 11 years) with sudden cardiac death while being monitored were analyzed. Thirty-eight patients were known to have coronary artery disease, 5 had cardiomyopathy, and 7 had aortic valve disease. Etiology remained unknown in 11 patients. Mean New York Heart Association functional class was 2.5 +/- 0.7. Thirty patients had received antiarrhythmic drugs and 32 had received digitalis. Sudden death occurred at rest in 73%. In the hours before death, repetitive ventricular arrhythmias were found in 50 patients (82%), with atrial fibrillation in 34%. Patients with bradyarrhythmic death (18%) had less complex ventricular …