1,720,971 research outputs found
AUTONOMIC PROFILE AND ARRHYTHMIC RISK STRATIFICATION AFTER SURGICAL REPAIR OF TETRALOGY OF FALLOT.
No full textBACKGROUND: Severe ventricular arrhythmias represent one of the main causes of mortality after repair of tetralogy of Fallot. Their appearance is primarily caused by the large ventricular scar created by surgical intervention. However, the role of autonomic activity as a modulating factor should be considered. The aim of our study was to evaluate this activity in a low-risk group of patients operated on for TOF and its correlation with the occurrence of sustained ventricular tachycardia.
METHODS AND RESULTS: The study group included 38 patients with a mean age of 31 +/- 10 years, selected out of 76 subjects operated on for total correction of tetralogy of Fallot. After a mean interval of 21.9 +/- 6 years from surgical procedure, they underwent electrocardiography, echocardiography, and time domain heart rate variability (HRV) analysis obtained by 24-hour Holter monitoring. Thirty-five healthy subjects comprised the control group for HRV analysis. During a mean follow-up of 6.2 +/- 3 years, 8 patients experienced episodes of sustained ventricular tachycardia. Among different HRV parameters, the standard deviation of all normal beat intervals showed a significant reduction in this group of patients (91.7 +/- 19 versus 133.4 +/- 46, P < .02). Echocardiographic examination demonstrated an increased left ventricular end diastolic volume (85.6 +/- 55 versus 61.3 +/- 13 mL/m(2), P < .05) and a reduced left ventricle ejection fraction (53.9 +/- 9 versus 61.0 +/- 6 %, P < .01) in arrhythmic patients. QRS duration was similar in patients with or without sustained ventricular tachycardia.
CONCLUSIONS: Patients after surgical correction of tetralogy of Fallot, considered to be at low risk, showed a significant incidence of severe ventricular arrhythmias. HRV analysis seems to be a useful method for identifying arrhythmic patients, and the standard deviation of all normal beat intervals appears to be the more helpful index
Long-term follow-up of the signal-averaged ECG in arrhythmogenic right ventricular cardiomyopathy: correlation with arrhythmic events and echocardiographic findings
Full text linkAIMS:
The aims of our study were to evaluate late potential changes during long-term follow-up in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) and to correlate these results with echocardiographic findings and sustained ventricular tachycardia (VT) occurrence.
METHODS AND RESULTS:
We studied 31 patients (22 males and 9 females; mean age 29+/-16) during 8 years of follow-up by signal-averaged ECG (SAECG) and echocardiography. Ten subjects experienced episodes of sustained VT. During follow-up, all the SAECG parameters showed a progressive significant increase in late potentials. In contrast, echocardiographic indices did not show evidence of relevant modifications. Patients with sustained VT were characterized by significantly lower left and right ventricular ejection fractions, longer values of filtered QRS at 25/40/80-250 Hz filters, and longer high-frequency low-amplitude (HFLA) signals at 25-250 Hz at baseline. The analysis of SAECG modification during follow-up indicated that only HFLA signals at 25-250 Hz increased significantly in the sustained VT group.
CONCLUSION:
We detected a progressive increase in delayed ventricular conduction by SAECG not associated with significant echocardiographic changes. Therefore, the conduction disturbance seems to increase independently from anatomical alterations. The baseline SAECG and echocardiographic parameters, more than their modifications during follow-up, appear to be useful in identifying patients with sustained VT
Age-related hemodynamic changes during vasovagal syncope
No full textObjective
The aim of our study was to identify specific age-related hemodynamic changes during upright tilt test in patients with vasovagal syncope.
Methods
We studied 115 subjects who were referred to us for unexplained syncope during 65° tilt with pharmacological challenge (s.l. nitrate) by noninvasive monitoring of blood pressure (Finometer). Two derived variables were also considered: total peripheral resistance and stroke volume. The patients were divided into 3 groups by age: Group 1, 10–30 yrs; Group 2, 31–50 yrs; and Group 3, > 51 yrs.
Results
The test was positive in 65 patients (57%). During the first 20 min of the test, older patients experienced lower increases in heart rate (p < 0.00001) and premature reduction of total peripheral resistance (p < 0.005) and systolic blood pressure (p < 0.005). Group 1 showed more pronounced decreases in stroke volume (p < 0.01). No differences emerged between negative and positive patients.
In the 5 min that preceded syncope, younger subjects experienced a distinct, transient increase in heart rate immediately before symptom onset (p < 0.005). Blood pressure was prematurely and progressively decreased in Group 3, whereas it decreased only in the 90 s prior to syncope in Groups 1 and 2 (p < 0.01).
Conclusions
Our results suggest that blunted sympathetic activation occurs during passive orthostatism in older patients. On the other hand, hemodynamic changes before symptom onset seem to indicate as in younger subjects syncope results from an excessive sympathovagal reaction, whereas in older subjects it is related to an overwhelming, progressive central vagal activity that is associated with a defective peripheral sympathetic activation
Contribution of decreased atrial function in the pathogenesis of neurally mediated syncope.
No full textOne of the most important mechanisms proposed in the pathogenesis of neurally mediated syncope considers the stimulation of myocardial mechanoreceptors as the final trigger leading to reflex hypotension and bradycardia. The aim of our study was to analyze the modifications of systolic and diastolic velocities of the left ventricle by tissue Doppler echocardiography, during the upright tilt test, to confirm the presence of an increased ventricular contractility before syncope. We evaluated 47 patients (mean age 43 years) with unexplained syncope and 13 healthy subjects. Three echocardiographic recordings were collected: at baseline, during the initial 5 minutes of the test, and after 15 minutes of tilt. The upright tilt test was positive in 28 patients. During the test, all of them had a similar, significant, progressive reduction of left ventricular end-diastolic volume, left atrial area, and left atrial volume. In contrast, the left ventricular ejection fraction showed an early, more pronounced decrease in those with positive tests. By tissue Doppler echocardiography, the systolic waves remained almost unchanged, and the early filling waves decreased similarly in those with positive or negative findings and the controls. In contrast, the atrial filling waves showed a significant decrease only in patients with positive tests. In conclusion, our study did not find increased ventricular contractility before syncope. In contrast, a decreased atrial contribution to ventricular filling characterized patients with positive upright tilt test results, which, we postulate, may be an important contributory factor to vasovagal syncope
Individual exposure to particulate matter and the short-term arrhythmic and autonomic profiles in patients with miocardial infarction
No full textAIMS:
Epidemiological studies show that peak exposure to air pollution is associated with increased morbidity and mortality from cardiovascular events. Panel and controlled exposure studies show that particulate matter (PM) may influence the parasympathetic regulation of the heart. The aim of this study was to concurrently measure individual exposure to PM of various sizes, heart rate variability (HRV), and electrical instability in patients with myocardial infarction.
METHODS AND RESULTS:
Personal exposures to PM(10), PM(2.5), and PM(0.25) was measured over 24 h in 39 patients (36 males, 3 females; mean age 60.3 years) with prior myocardial infarction (>6 months). Simultaneously, a 24 h ECG was recorded and then analysed for HRV and ventricular arrhythmias. Breath condensate and blood samples also were collected at the end of monitoring to measure several indexes of inflammation. Negative correlation was found between HRV and exposure to PM(0.25) in a group of patients not taking beta-blockers. More severe ventricular arrhythmias were observed at the highest concentrations of PM(10) and PM(2.5). Indexes of inflammation in either breath condensate or blood did not correlate with PM exposures.
CONCLUSION:
Our study shows that exposure to ultrafine particles is associated with autonomic dysregulation in selected patients with myocardial infarction. More severe arrhythmias occur at the highest exposures to larger particles. Nevertheless, the underlying mechanisms remain hypothetical because inflammation may be evoked by PM or be related to the disease itself
Heart rate variability evolution during 5 years follow-up in patients submitted to orthotopic heart transplantation
No full textHEART-RATE-VARIABILITY IN PATIENTS WITH ORTHOTOPIC HEART-TRANSPLANTATION - LONG-TERM FOLLOW-UP
No full textHeart rate variability in arrhythmogenic right ventricular cardiomyopathy correlation with clinical and prognostic features
No full textI.F. 1.13
Origin of recurrent syncope in patient with right ventricular outflow tractarrhythmias: evidence of autonomic modulation of the ectopic foci
No full textVentricular arrhythmias and autonomic profile in patients with primry pulmonary hypertension
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