Naomi Nussinovitch

Evaluating reliability of ultra-short ECG indices of heart rate variability in diabetes mellitus patients.

Our aim was to investigate the reliability of ultra-short HRV in patients with DM. A good correlation was found between the 1 minute and 5 minute parameters for maximal-RR, minimal-RR, average-RR, SDNN, RMSSD, pNN50, and total power. Also, a good correlation between 10 second and 5 minute parameters was found for maximal-RR, minimal-RR, average-RR, and RMSSD. We suggest that certain ultra-short HRV parameters can be used efficiently in DM patients for autonomic evaluation.

Homocysteine levels in hypertensive patients with a history of cardiac or cerebral atherothrombotic events.

Hypertension is one of the most important risk factors for cardiovascular morbidity and mortality. Recently it has been suggested that the amino acid homocysteine contributes to this process. This study evaluates whether elevated plasma levels of homocysteine in hypertensive patients are associated with increased risk for cardiovascular events. Fifty hypertensive patients with a documented history of cerebral or cardiac events were age and gender matched to 50 hypertensive patients with no evidence of any cerebral or cardiac event. Demographic details, duration of hypertension, presence of other risk factors, and use of antihypertensive medications were recorded for each patient. Plasma levels of homocysteine were measured by high-performance liquid chromatography technology. The two groups had similar demographic parameters, with a mean age of 64.6 +/- 9.4 years. Patients with cardiovascular events were more likely to be past smokers and to have been treated with calcium antagonists, aspirin, and nitrates. Homocysteine levels were 12.1 +/- 5.8 micromol/L in those with documented cardiovascular disease and 11.1 +/- 4.7 micromol/L in those without (P = NS). Levels of plasma homocysteine were higher in those with hypercholesterolemia (P = .03) and in smokers, and tended to be lower in those who used beta-blockers, angiotensin converting enzyme (ACE) inhibitors, diuretics, and nitrates. Thus, hyperhomocysteinemia is not a feature of hypertensive patients with atherothrombotic events and there is no support for additive or synergistic effects between these two independent risk factors.

Heart rate variability in familial Mediterranean fever

Familial Mediterranean fever (FMF) is a hereditary disease, characterized by recurrent episodes of fever and polyserositis. Heart rate variability (HRV) is a powerful, simple and reliable technique to evaluate autonomic nervous system function. Previous studies of physiologic parameters during tilt-test have suggested that patients with FMF have abnormal cardiovascular reactivity and occult dysautonomia. Prompted by these findings, the present study sought to evaluate HRV in patients with FMF, at rest and in the standing position. The study sample included 34 patients with FMF and 34 sex- and age-matched control subjects. All underwent electrocardiography according to strict criteria. HRV parameters were computed with custom-made software. There was no significant difference in HRV parameters, in either the supine or standing position, between the FMF and control groups. In both groups, the upright position was associated with a significant decrease, when compared with the supine position, in maximal RR interval, minimal RR, average RR, root square of successive differences in RR interval, number of intervals differing by >50xa0ms from preceding interval (NN50), NN50 divided by total number of intervals (pNN50) and high-frequency components as well as a significant increase in average heart rate, very low frequency or low-frequency components, low-frequency/high-frequency components ratio and total power. In conclusion, patients with FMF who are continuously treated with low-dose colchicine have not developed amyloidosis and have normal HRV parameters in the supine and upright position. Further investigation of occult dysautonomia in FMF is needed.

P wave dispersion in familial Mediterranean fever

Familial Mediterranean fever (FMF) is a hereditary disease characterized by recurrent and self-terminated attacks of fever and polyserositis. A recent study found that FMF patients had an abnormally high P wave duration and P wave dispersion, markers for supraventricular arrhythmogenicity. The aim of our study was to further evaluate atrial dispersion in FMF patients. The study group consisted of 26 patients with uncomplicated FMF and age- and sex-matched control subjects. All participants underwent 12-lead electrocardiography under strict standards. P wave length and P wave dispersion were computed from a randomly selected beat and from an averaged beat constructed from 7 to 12 beats, included in a 10-s ECG. No statistically significant differences were found between the groups in minimal, maximal, and average P wave duration and P wave dispersion calculated either from a random beat or averaged beats. During 6xa0months of follow-up, no supraventricular arrhythmias were documented in either group. FMF patients who are continuously treated with colchicine and do not develop amyloidosis have normal atrial conduction parameters and therefore seemingly do not have an increased electrocardiographic risk of atrial fibrillation.

The Efficiency of 10-Second Resting Heart Rate for the Evaluation of Short-Term Heart Rate Variability Indices

Background: u2002High values of resting heart rate were found to be correlated with adverse outcomes in various patient groups. Heart rate variability (HRV) is a reliable technique in determining autonomic nervous system function. Our aim was to evaluate whether a 10‐second resting heart rate obtained from a resting electrocardiogram (ECG), could be used as a reliable evaluation of short‐term HRV.

Cerebrospinal fluid lactate dehydrogenase isoenzymes in children with bacterial and aseptic meningitis.

Differentiation of bacterial from aseptic meningitis may be difficult. Our aim was to determine the pattern of distribution of lactate dehydrogenase (LDH) isoenzymes in the cerebrospinal fluid (CSF) of patients with bacterial and aseptic meningitis. One hundred and fifty-seven patients with suspected meningitis were enrolled in the study. They were divided into 3 groups according to the culture- or bacterial antigen assay-proven diagnosis and CSF findings: bacterial meningitis (n = 31), aseptic meningitis (n = 65), and non-meningitis (n = 61). Total LDH level and percentages of LDH isoenzymes in the CSF were measured in each patient. Each group showed a distinct LDH isoenzyme distribution pattern, with a statistically significant difference among the groups in the percentages of the various isoenzymes. Compared with the non-meningitis group, total LDH activity in the CSF was high in the aseptic meningitis group (49.82+/-35.59 U/L, P < 0.001) and exaggerated in the bacterial meningitis group (944.53+/-112.3 U/L, P < 0.001). Low LDH-2 levels were unique to bacterial meningitis (P < 0.01), whereas high LDH-3 levels were characteristic of aseptic meningitis (P < 0.05). Both groups had low levels of LDH-1 and high levels of LDH-4 and LDH-5. In conclusion, the LDH isoenzyme pattern may be of clinical diagnostic value in meningitis, particularly when culture results are pending.

QT dispersion in amyloidosis due to familial Mediterranean fever.

Cardiac amyloid deposition in FMF may cause increased QT dispersion (QTd), a marker for cardiac arrhythmias. The aim of this study was to further evaluate repolarization dispersion in familial Mediterranean fever (FMF) with amyloidosis. Findings on 12-lead electrocardiography were compared between 18 patients with FMF-amyloidosis and 18 age- and sex-matched control subjects. Repolarization and dispersion parameters were computed with designated computer software, and results of the 5 beats were subsequently averaged. There were no statistically significant differences between the groups as to average corrected QT interval length, average QTd interval, average QT corrected dispersion, or QT dispersion ratio. JT dispersion and JT corrected dispersion were also similar in both groups. In conclusion, patients with FMF-amyloidosis seem to have QT and JT dispersion parameters similar to those of healthy subjects. Future research and longer follow-ups should be conducted in order to evaluate the prognostic importance of repolarization dispersion parameters in amyloidosis of FMF.

QT interval variability in familial Mediterranean fever: a study in colchicine-responsive and colchicine-resistant patients.

The association between familial Mediterranean fever (FMF), early atherosclerosis, and electrocardiographic markers for arrhythmias remains controversial. There are conflicting results as to the occurrence of high QT dispersion in FMF. The aim of the present study was to further investigate repolarization dynamics and other repolarization-associated pro-arrhythmogenic markers in FMF patients. To explore repolarization in FMF, patients who responded well to colchicine and patients who had not responded to colchicine, yet were amyloidosis-free, were included. We aimed to evaluate whether increased inflammatory burden, a characteristic of non-responsive patients, was specifically associated with abnormal repolarization. Included in the study were 53 FMF patients (27 colchicine non-responders) and 53 age- and sex-matched control subjects. Electrocardiograms were performed under strict standards. QT variability parameters were computed with custom-made computer software. No significant difference in any of the QT dynamic parameters was found in either FMF group compared with the healthy controls. Mean values of QT variability index, regardless of colchicine response, were similar to previously published results for healthy persons. In conclusion, patients with FMF who are continuously treated with colchicine and have not developed amyloidosis, regardless of their clinical response, have normal QT variability parameters, indicating normal repolarization dynamics and suggesting no increased risk of repolarization-associated cardiac arrhythmias.

Normal QT dispersion in colchicine-resistant familial Mediterranean fever (FMF)

The association between familial Mediterranean fever (FMF) and subclinical cardiac disease remains controversial. The aim of the current study was to evaluate whether FMF patients, who do not respond to colchicine treatment, and thereby endure persistent inflammation, have increased QT dispersion (QTd) values. Twenty-two FMF patients and 22 age- and sex-matched control subjects were included in the study. Repolarization and QT dispersion parameters were computed from 12-lead ECG recording using designated computer software, and results of five beats were subsequently averaged. Both FMF patients and controls had similar comorbidities, similar values of average QT, average corrected QT interval length, average QTd interval, average QT corrected dispersion, QT dispersion ratio, JT dispersion (JTd), and JT corrected dispersion. In conclusion, FMF patients who were unresponsive to colchicine treatment and did not develop amyloidosis had normal QTd and JTd parameters, indicating a non-increased risk for repolarization-associated ventricular arrhythmias.

Late Ventricular Potentials and QT Dispersion in Familial Dysautonomia

Familial dysautonomia is a worldwide disorder characterized by maldevelopment and dysfunction of the autonomic and sensory systems. Despite major improvements in disease management in recent years, sudden death remains the cause of death in up to 43% of patients. The aim of this study was to evaluate electrocardiographic markers of sudden death in familial dysautonomia. A comparative case series design was used. Electrocardiographic measurements were performed in 13 patients with familial dysautonomia, 7 male and 6 female, aged 9–46xa0years. QT was measured from all leads and corrected QT (QTc) was calculated with the Bazett formula. QT dispersion (QTd), a marker of arrhythmogenicity, was calculated and corrected for heart rate. Late ventricular potential parameters, predictive of arrhythmias, were calculated as well. Findings were compared to a matched control group using the Mann–Whitney–Wilcoxon test. A prolonged QT interval was noted in 30.7% of patients. Several QT dispersion parameters were significantly abnormal in the study group compared to the controls. All late potential parameters were within normal range in both groups. In conclusion, patients with familial dysautonomia commonly have electrocardiographic abnormalities and may be at a higher risk for adverse cardiac events.