Progressive Impairment of Autonomic Control of Heart Rate in Patients with Multiple Sclerosis

BACKGROUND

Data regarding the autonomic control of heart rate in multiple sclerosis (MS) patients depending on the disease duration are lacking in the literature. The goal of this study was to evaluate differences in heart rate variability (HRV) in patients with MS according to the duration of the disease.

METHODS

The study included 39 patients (23 female and 16 male; median age 42 years, range 34-53 years) with relapsing-remitting MS (RRMS) in stable phase and 39 age- and sex-matched healthy controls. RRMS patients were divided into two groups: group 1 with 21 patients within 5 years and group 2 with 18 patients with >5 years from the diagnosis of MS. HRV analysis was done with 24-h Holter ECG.

RESULTS

Patients with RRMS had a significantly lower overall HRV than controls: SDNN 91+/-18 msec vs. 135+/-24 msec, p<0.001. RRMS patients with lower duration of disease (Group 1) had all higher HRV parameters except LF/HF ratio compared with RRMS patients with >5 years from the diagnosis of MS (Group 2): SDNN 94+/-24 vs. 88+/-21 msec, p=0.008; TP 2028+/-1326 vs. 1683+/-1017 ms2, p=0.006.

CONCLUSIONS

Results of the study suggested that the autonomic control of heart rate depends on the disease duration in RRMS patients. Longer disease duration led to progressive impairment of cardiac autonomic balance in MS patients.

Characteristics of heart rate variability in war veterans with post-traumatic stress disorder after myocardial infarction

OBJECTIVE

The goal of the study was to evaluate differences in heart rate variability (HRV) among post-myocardial infarction (MI) patients, depending on their participation in the Croatian war and on established diagnoses of post-traumatic stress disorder (PTSD).

METHODS

The study included 34 male war veterans with diagnosed PTSD who had suffered a first MI and 34 age-matched post-MI patients without PTSD. Cardiac autonomic balance was evaluated through HRV analysis.

RESULTS

There were no differences in the mean R-R interval or overall HRV between the analyzed groups. Post-MI patients with PTSD had lower values for the square root of the mean of squared successive differences in R-R intervals (p = 0.02), the percentage of R-R intervals that were > or =50 milliseconds different from the previous interval (p = 0.03), and the high-frequency component (p = 0.03) but had higher values for the low-frequency component (p = 0.01) and the low-frequency/high-frequency ratio (p = 0.02), compared with post-MI patients without PTSD.

CONCLUSION

Post-MI patients with PTSD have higher sympathetic and lower parasympathetic heart rate modulation activity, compared with patients with MI and no PTSD.

Left ventricular diastolic function in diabetes mellitus type 2 patients: correlation with heart rate and its variability

AIMS

To assess the prevalence of left ventricular diastolic dysfunction in a population of patients with type 2 diabetes mellitus; to determine correlation of diastolic dysfunction with heart rate and its variability.

METHODS

The study included 202 patients with type 2 diabetes mellitus. Echocardiography was performed with special reference to diastolic function, and heart rate variability was analysed using standard deviation of normal RR intervals, root mean square of successive differences and percentage of successive R-R intervals greater than 50 ms (pNN 50 %) in a 24-h electrocardiogram recording.

RESULTS

Diastolic dysfunction is present in 79 % of type 2 diabetes mellitus patients: grade 1 in 52 %, grade 2 in 26 % and grade 3 in 1 % of patients. The subjects with grade 1 diastolic dysfunction had a statistically significantly higher heart rate variability compared with those with grade 2 diastolic dysfunction (LSD, post hoc test, p = 0.001). In the group with diastolic dysfunction, grade 2 reduced heart rate variability was recorded in 83 % of patients (37 and 7 % for grade 1 and normal diastolic function). An increase in the severity of diastolic dysfunction was associated with decreased heart rate variability and increased heart rate.

CONCLUSION

Progression of diastolic dysfunction is associated with a significantly greater prevalence of reduced heart rate variability, which is accompanied by increased heart rate.

Changes in Heart Rate Variability after Coronary Artery Bypass Grafting and Clinical Importance of These Findings

Heart rate variability is a physiological feature indicating the influence of the autonomic nervous system on the heart rate. Association of the reduced heart rate variability due to myocardial infarction and the increased postinfarction mortality was first described more than thirty years ago. Many studies have unequivocally demonstrated that coronary artery bypass grafting surgery generally leads to significant reduction in heart rate variability, which is even more pronounced than after myocardial infarction. Pathophysiologically, however, the mechanisms of heart rate variability reduction associated with acute myocardial infarction and coronary artery bypass grafting are different. Generally, heart rate variability gradually recovers to the preoperative values within six months of the procedure. Unlike the reduced heart rate variability in patients having sustained myocardial infarction, a finding of reduced heart rate variability after coronary artery bypass surgery is not considered relevant in predicting mortality. Current knowledge about changes in heart rate variability in coronary patients and clinical relevance of such a finding in patients undergoing coronary artery bypass grafting are presented.

The impact of thyroid hormone replacement therapy on left ventricular diastolic function in patients with subclinical hypothyroidism

OBJECTIVE

Subclinical hypothyroidism (SH) is associated with a moderately elevated risk of heart failure events among older adults. The objective of our prospective study was to assess the impact of thyroid hormone replacement therapy (HRT) with low doses of L-thyroxine (6.25-25 µg/day) on left ventricular diastolic function in patients with SH.

MATERIALS AND METHODS

33 patients with SH and 25 healthy controls were involved. All participants underwent standard echocardiography and Doppler imaging at baseline and, the patient group, also after a course of HRT.

RESULTS

At baseline, patients with SH showed significantly lower E (0.79 ± 0.22 vs. 0.93 ± 0.19, p < 0.001), E/A ratio (1.19 ± 0.29 vs. 1.31 ± 0.25, p < 0.003), and higher intraventricular septum thickness (IVST) (0.99 ± 0.14 vs. 0.89 ± 0.18, p < 0.001) in comparison with healthy controls. After 6 months of therapy, the E/A ratio underwent significant increase (1.28 ± 0.21 vs. 1.19 ± 0.29, p < 0.001), while the IVS displayed a robust reduction (0.92 ± 0.16 vs. 0.99 ± 0.14, p < 0.001).

CONCLUSIONS

HRT with low-dosed L-thyroxine may improve left ventricular diastolic function in patients with SH.

Current concept in the diagnosis, treatment and rehabilitation of patients with congestive heart failure

Heart failure (HF) is a major public health problem with a prevalence of 1%-2% in developed countries. The underlying pathophysiology of HF is complex and as a clinical syndrome is characterized by various symptoms and signs. HF is classified according to left ventricular ejection fraction (LVEF) and falls into three groups: LVEF ≥ 50% - HF with preserved ejection fraction (HFpEF), LVEF < 40% - HF with reduced ejection fraction (HFrEF), LVEF 40%-49% - HF with mid-range ejection fraction. Diagnosing HF is primarily a clinical approach and it is based on anamnesis, physical examination, echocardiogram, radiological findings of the heart and lungs and laboratory tests, including a specific markers of HF - brain natriuretic peptide or N-terminal pro-B-type natriuretic peptide as well as other diagnostic tests in order to elucidate possible etiologies. Updated diagnostic algorithms for HFpEF have been recommended (H2FPEF, HFA-PEFF). New therapeutic options improve clinical outcomes as well as functional status in patients with HFrEF (e.g., sodium-glucose cotransporter-2 - SGLT2 inhibitors) and such progress in treatment of HFrEF patients resulted in new working definition of the term “HF with recovered left ventricular ejection fraction”. In line with rapid development of HF treatment, cardiac rehabilitation becomes an increasingly important part of overall approach to patients with chronic HF for it has been proven that exercise training can relieve symptoms, improve exercise capacity and quality of life as well as reduce disability and hospitalization rates. We gave an overview of latest insights in HF diagnosis and treatment with special emphasize on the important role of cardiac rehabilitation in such patients.

The dynamics of soluble Fas/APO 1 apoptotic biochemical marker in acute ischemic stroke patients

PURPOSE

Until recently, neuronal death in ischemic stroke infarction was ascribed exclusively to necrotic process. However, experimental animal models of cerebral ischemia suggest apoptosis to play a role in the pathogenesis of cerebral infarction. The aim of this study was to determine the level and monitor the dynamics of soluble Fas/APO 1 (sFas/APO 1) in serum and cerebrospinal fluid of acute ischemic stroke patients.

MATERIAL AND METHODS

This prospective study included 23 patients with first ever, computed tomography verified acute ischemic stroke and 20 control subjects with other functional neurologic disorders. Serum and cerebrospinal fluid sFas/APO 1 levels were determined on several occasions. Blood samples were obtained on day 1, 3 and 12, and lumbar puncture on day 3 and 12 of disease onset. Quantitative sandwich ELISA method was used on sFas/APO 1 determination.

RESULTS

On day 1 of disease onset, serum and cerebrospinal fluid sFas/APO 1 levels were significantly higher in stroke patients as compared to control subjects, and then gradually declined during the period of monitoring.

CONCLUSION

Study results confirmed the dynamic pattern of sFas/APO 1 in serum and cerebrospinal fluid of patients with acute ischemic stroke, suggesting the possible role of apoptosis in the pathogenesis of cerebral infarction.

Heart rate variability in patients after cardiac valve surgery

The aim of study was to analyze heart rate variability (HRV) after different cardiac valve surgery procedures and the prognostic values of these findings. This study included 101 consecutive patients who underwent surgical implantation for an artificial valve. The mean age of the patients was 62 ± 10 years. An aortic valve was implanted in 65 patients. A mitral valve was implanted in 36 patients. HRV was analyzed from 24 hours Holter electrocardiographic (ECG) records. The time from the operation to the recording of Holter ECG and measuring HRV was 3.8 ± 1.4 months. After discharged from stationary cardiac rehabilitation, all involved patients were contacted to provide data on their health in the follow-up period (33 ± 21 months). A total of 46 patients with an implanted artificial valve had decreased overall HRV or standard deviation of all normal R-R intervals (SDNN) < 93 ms. Patients with an implanted artificial mitral valve had a shorter RR interval (817 ± 122 vs. 863 ± 122ms, p=0.03) and lower values of total power (1166 ± 1888 vs. 2802 ± 3601 ms2, p<0.001) compared to patients with an implanted artificial aortic valve. The results of study show that several months after cardiac surgery, almost half of the patients with an implanted artificial valve have decreased HRV. However, postoperative decreased HRV in those patients have no importance in long-term prediction of mortality rate.

Heart rate variability differences in post-myocardial infarction patients based on initial treatment during acute phase of disease

The aim of study was to asses the heart rate variability (HRV) differences in 128 post-myocardial infarction (MI) patients based on initial treatment during acute phase of disease. The patients were divided into groups: group 1 patients who underwent primary PCI, group 2 patients who received fibrinolysis and group 3 patients who were treated conservatively. In comparison with groups 2 and 3, group 1 patients had all HRV analyzed parameters higher except for LF/HF ratio. The results of study suggest that patients who were treated by primary PCI had better preserved autonomic cardiac function compared with patients who received fibrinolysis or those who were treated conservatively in the acute phase of MI.

Heterophile antibodies, false-positive troponin, and acute coronary syndrome: a case report indicating a pitfall in clinical practice

BACKGROUND

Heterophile antibodies are one of the most common causes of false-positive troponin.

CASE SUMMARY

We report a case of a 53-year-old woman with false-positive troponin elevation and a clinical presentation understood and treated as non-ST-elevation acute coronary syndrome. Because of chronic basal elevation of troponin (at a 'plateau' level) and chest pain, the patient underwent several invasive coronary angiograms until false-positive increase of troponin due to heterophile antibodies was suspected. Borderline stenosis of a left circumflex coronary artery found on first coronary angiogram was a coincidental finding and heterophile antibodies in the patient's serum were confirmed.

DISCUSSION

This interesting case report aims to remind the clinicians about the possibility of false-positive troponin level due to laboratory analytical interference caused by heterophile antibodies. In this case, it is important to suspect false-positive troponin elevation, even when coronary artery disease is found. This rare and less mentioned and/or recognized cause of troponin elevation may lead to unnecessary invasive diagnostics and aggressive treatment of patients.

Different cut-off points of decreased heart rate variability for different groups of cardiac patients

BACKGROUND

Heart rate variability (HRV) differs by the type and stage of the disease, by age, by environment, and so on. Criteria for normal, moderately changed and pathologic values of HRV lack for routine clinical work with different groups of cardiac patients.

METHODS

Twelve time and frequency domain HRV variables were analysed from 24-h Holter ECG monitoring in 2578 consecutive patients of both sexes (57% male) aged 15-91 (mean 54 +/- 13) years. Fifty-nine per cent of the patients were hospital out-patients, 15% came from the cardiac unit of an internal medicine department and 26% were undergoing stationary cardiac rehabilitation. Arrhythmias of aetiology other than coronary artery disease predominate in out-patients and coronary artery disease in in-patients. Limits of moderately and pathologically changed values were determined according to biostatistical principles.

RESULTS

HRV differed by the age, sex and type of patients (MANOVA P < 0.001). Heart rate and all HRV measures decreased with age. Females had a higher heart rate but more pronounced vagally modulated activity than males. Out-patients had better HRV than in-patients. The cut-off level for a pathologic standard deviation of the normal R-R interval (a measure of overall HRV) ranged from 75 ms in female out-patients to 44 ms in male patients from the cardiac unit. Different cut-points for 12 HRV measures were obtained for 12 sub-groups of patients.

CONCLUSION

In view of the HRV differences between different cardiac patients, different limits of normal and decreased HRV are proposed for daily practice.

Functional parameters but not heart rate variability correlate with long-term outcomes in St-elevation myocardial infarction patients treated by primary angioplasty

BACKGROUND

Depressed heart rate variability (HRV) is usually considered a negative long-term prognostic factor after acute myocardial infarction. Anyway, most of the supporting research was conducted before the era of immediate reperfusion by percutaneous coronary intervention (PCI). Main aim of this study was to evaluate if HRV still retains prognostic significance in our era of immediate PCI.

METHODS AND RESULTS

Two weeks after STEMI treated by primary PCI, time-domain HRV was assessed from 24-h Holter recordings in 186 patients: markedly depressed HRV (SDNN <70ms or <50ms) was present in 16% and in 5% of cases, respectively; patients with left ventricle ejection fraction (LVEF) <40% presented more often SDNN values in the lowest quartile. Physical performance was also assessed, by 6-minute walk tests (6MWT) and by cardiopulmonary exercise test (CPET). After >2years from infarction, occurrence of major clinical events (MCE) was investigated. Cases with or without MCE did not differ by initial HRV parameters; Kaplan-Meier events-free survival curves were similar between patients with lowest quartile SDNN and the remaining ones (χ² 0.981, p=0.322). By the contrary, events-free survival was worse if patients walked shorter distances at 6MWT (χ² 6.435, p=0.011), developed poorer ventilatory efficiency at CPET (χ² 10.060, p=0.002), or presented LVEF <40% (χ² 7.085, p=0.008).

CONCLUSIONS

In primary-PCI STEMI patients, markedly abnormal HRV was found in a small percentage of cases. HRV seems to have lost its prognostic significance, while parameters indicating LV function (LVEF and physical performance) could allow better prognostication in primary-PCI STEMI patients.

TORSADES DE POINTES IN ELDERLY PATIENT WITH PAROXYSMAL ATRIAL FIBRILLATION TREATED BY SHORT-TERM PARENTERAL AMIODARONE THERAPY

One of the drugs that are widely used in the treatment of atrial fibrillation is amiodarone. Despite considerable prolongation of the corrected QT interval and a substantial degree of bradycardia, amiodarone exhibits a remarkably low frequency of pro-arrhythmic events and <1.0% incidence of torsades de pointes, mostly after long-term usage. We present a case of an 80-year-old female with paroxysmal atrial fibrillation accompanied by acute heart failure treated by short-term parenteral amiodarone therapy and development of torsades de pointes.

ANTIPLATELET THERAPY AFTER CORONARY ARTERY BYPASS GRAFT SURGERY - UNEVENNESS OF DAILY CLINICAL PRACTICE

Antiplatelet therapy is an integral part of optimal medicamentous therapy in patients with coronary artery disease. The strategy of antiplatelet/anticoagulant therapy is adjusted (combination of drugs, dosing and duration of therapy) depending on the stage of the disease (acute coronary syndrome with percutaneous coronary intervention, chronic coronary syndrome, or coronary surgical revascularization) and comorbidity of each patient (e.g., atrial fibrillation, left ventricular thrombus, etc.). Guidelines and clinical practice in particular are not uniform and specific regarding dual antiplatelet therapy in patients undergoing coronary artery bypass grafting, especially in the setting of chronic coronary syndrome.

[Tako-Tsubo cardiomyopathy; reversible left ventricular dysfunction mimicking acute myocardial infarction with ST-elevation]

Tako-Tsubo cardiomyopathy is still en entity of unknown etiology and pathophysiology which clinically manifests with sudden, severe chest pain and/or dyspnea. It is generally triggered by emotional or physical stress and most cases are reported in postmenopausal women. Electrocardiographic changes are similar to acute myocardial infarction with ST-elevation, laboratory markers of myocardial lesion are usually mild to moderately high, and coronary angiography shows no significant pathomorphological changes of epicardial coronary arteries. Ventriculography and echocardiography show reversible akinesis and ballooning of the left ventricular apex with reduced ejection fraction which is usually normalized within 2-4 weeks. Generally, Tako-Tsubo cardiomyopathy has a good prognosis, in-hospital mortality rate is about 1%. In this article, we present a review about todays knowledge on Tako-Tsubo cardiomyopathy.

The effect of 3-weeks stationary cardiac rehabilitation on plasma lipids level in 444 patients with coronary heart disease

The aim of this study was to investigate the effect of 3-weeks stationary cardiac rehabilitation on plasma lipids level in patients with CHD. The study included 444 consecutive patients (364 male and 80 female, mean age 58 +/- 9 year) with CHD who underwent 3-weeks stationary cardiac rehabilitation. Patients were divided into groups depending on their baseline levels of cholesterol and medication therapy: patients with normal (< 5 mmol/L, group I, 129 patients) and elevate plasma level of Total cholesterol (> 5 mmol/L, group II, 315 patients) and subgroups Ia and IIa (with statin in therapy), Ib and IIb (without statin in therapy). After 3-weeks cardiac rehabilitation, the levels of Total cholesterol 5.75 +/- 1.34 vs. 5.17 +/- 1.08 mmol/l; p < 0.001, triglycerides 2.04 +/- 1.33 vs. 1.81 +/- 1.06 mmol/L; p = 0.004, LDL-cholesterol 3.77 +/- 1.14 vs. 3.21 +/- 0.96 mmol/L; p < 0.001 were significantly lower while the level of HDL-cholesterol 0.94 +/- 0.28 vs. 0.99 +/- 0.27 mmol/L; p = 0.008 were significantly higher in comparison with the baseline values. Furthermore, we found significant changes in lipid profile at the end of rehabilitation in each group of patients compared with the baseline values. There were no significant differences in plasma lipids level between group of patients with or without statin in therapy at the end of rehabilitation. The results of this study suggest that moderate regular physical activity and diet alone or in combination with hypolipidemic drugs already after 3 weeks have a favourable effect on plasma lipids level and should be propagate in the prevention of CHD.