Elevated troponin I level assessed by a new high-sensitive assay and the risk of poor outcomes in patients with acute heart failure.

BACKGROUND: The interpretation and clinical usefulness of elevated levels of cardiac troponins in acute heart failure (AHF) remain controversial. We aimed to characterize the relationship between changes in cardiac troponin I (measured using a new high-sensitive immunoassay by single-molecule counting technology, Singulex, Alameda, USA; hs-TnI) during first 48h of hospital stay and patients' characteristics and the outcomes. METHODS AND RESULTS: We measured hs-TnI at baseline, after 24 and 48h in 130 AHF patients (mean age: 65±13years, 77% men). The percentage of patients with elevated hs-TnI (i.e., above the upper reference limit [URL]>10.19pg/mL) were: on admission - 59%, after 24h - 61%, and after 48h - 58%. Elevated baseline level of hs-TnI was associated with more severe dyspnoea on admission but neither peak level nor changes in hs-TnI during first 48h were related to the dyspnoea severity or magnitude of dyspnoea relief. During 1-year follow-up there were 32 (25%) cardiovascular deaths. Neither absolute baseline nor peak values of hs-TnI predicted cardiovascular mortality. Only changes in hs-TnI were independently associated with cardiovascular mortality with the strongest relationship seen in peak change in hs-TnI: patients with an increase vs. remaining patients - hazard ratio (95% confidence interval): 3.22 (1.52-6.82)p=0.002. CONCLUSIONS: Using the new assay (proved to be more sensitive that the other available troponin assays) we observed that approximately 60% of patients with AHF presented elevated hs-TnI above URL during first 48h of hospital stay. Only significant increase in hs-TnI predicted cardiovascular mortality.

Anaemia is an independent predictor of poor outcome in patients with chronic heart failure.

BACKGROUND: Mild anaemia frequently occurs in patients with chronic heart failure (CHF), particularly in the advanced stages of the disease. The correction of anaemia with erythropoietin is a therapeutic possibility. The aim of this study was to assess prospectively the relationship between the prevalence of anaemia (haemoglobin level18 months in all survivors), and the end-point of the study was all-cause mortality. RESULTS: A total of 176 patients were enrolled (mean age: 63 years, New York Heart Association (NYHA) classification I/II/III/IV: 15/81/51/29; left ventricular ejection fraction (LVEF): 42%, ischaemic aetiology in 62%). In the whole population the mean haemoglobin level was 140+/-15 g/l. Anaemia was found in 18 (10%) patients, and was significantly more common in women than in men (18 vs. 7%, respectively, P=0.02) and in those with most severe CHF symptoms (frequency in NYHA I/II/III/IV: 0/9/10/21%, respectively; NYHA IV vs. I-III, P=0.03), but not related to the other clinical indices. Univariate analysis revealed NYHA class III-IV (hazard ratio 3.8, 95% CI: 1.6-8.9, P=0.003), low LVEF <35% (hazard ratio 2.3, 95% CI: 1.0-4.9, P=0.04) and anaemia (hazard ratio 2.9, 95% CI: 1.2-7.2, P=0.02) as predictors of 18-month mortality. In multivariate analysis, anaemia remained an independent predictor of death when adjusted for NYHA class and LVEF (hazard ratio: 2.6, 95% CI: 1.0-6.5, P=0.04). In anaemic patients, 18-month survival was 67% (95% CI: 45-89%) compared to 87% (81-92%) in patients with a normal haemoglobin level (P=0.016). CONCLUSIONS: Mild anaemia is a significant and independent predictor of poor outcome in unselected patients with CHF. Correction of low haemoglobin level may become an interesting therapeutic option for CHF patients.

Peripheral chemoreceptor hypersensitivity: an ominous sign in patients with chronic heart failure.

BACKGROUND: Peripheral chemoreceptor hypersensitivity is a feature of abnormal cardiorespiratory reflex control in chronic heart failure (CHF) and may contribute to sympathetic overactivity, attenuated baroreflex sensitivity (BRS), and excessive ventilation during exercise. We studied whether augmented peripheral chemosensitivity carries independent prognostic significance. METHODS AND RESULTS: We assessed peripheral chemosensitivity (ventilatory response to hypoxia using transient inhalation of pure nitrogen) and BRS (phenylephrine and spectral methods) in 80 consecutive CHF patients (age 58+/-9 years; left ventricular ejection fraction [LVEF] 24+/-12%; peak oxygen consumption [peak VO(2)] 18+/-7 mL(-1). min(-1)). CHF patients demonstrated augmented peripheral chemosensitivity and decreased BRS (all P<0.01 versus reference values). During follow-up (median 41 months, >3 years in all survivors), 37 patients died. High peripheral chemosensitivity (>0.72 L. min(-1). %SaO(2)(-1)) predicted impaired survival (hazard ratio 3.2, 95% CI 1.6 to 6.0, P=0.0006). In the 27 patients (34%) with high peripheral chemosensitivity, 3-year survival was 41% (95% CI 22% to 60%) compared with 77% (66% to 89%) in 53 patients with normal chemosensitivity (P=0.0002). In multivariate analyses, augmented chemosensitivity independently predicted death (hazard ratio 2.8, 95% CI 1.5 to 5.5, adjusted for age, peak VO(2), and VE/VCO(2) [P=0.002]; hazard ratio 2.6, 95% CI 1.3 to 5.1, adjusted for age, LVEF, and peak VO(2) [P=0.008]). Depressed BRS was related to unfavorable prognosis in univariate analysis (P=0.05) but not in multivariate analyses. CONCLUSIONS: Hypersensitivity of the peripheral chemoreceptors independently predicts adverse prognosis in ambulatory patients with CHF. This hyperactive excitatory reflex, through its inhibitory effect on the baroreflex, may be the reason for the previously observed prognostic association of the latter.

Enhanced ventilatory response to exercise in patients with chronic heart failure and preserved exercise tolerance: marker of abnormal cardiorespiratory reflex control and predictor of poor prognosis.

BACKGROUND: In patients with chronic heart failure (CHF) and preserved exercise tolerance, the value of cardiopulmonary exercise testing for risk stratification is not known. Elevated slope of ventilatory response to exercise (VE/VCO(2)) predicts poor prognosis in advanced CHF. Derangement of cardiopulmonary reflexes may trigger exercise hyperpnea. We assessed the relationship between cardiopulmonary reflexes and VE/VCO(2)and investigated the prognostic value of (VE/VCO(2)) in CHF patients with preserved exercise tolerance. METHODS AND RESULTS: Among 344 consecutive CHF patients, we identified 123 with preserved exercise capacity, defined as a peak oxygen consumption (PEAK VO(2)) >/=18 mL. kg(-1). min(-1) (age 56 years; left ventricular ejection fraction 28%; peak VO(2) 23.5 mL. kg(-1). min(-1)). Hypoxic and hypercapnic chemosensitivity (n=38), heart rate variability (n=34), baroreflex sensitivity (n=20), and ergoreflex activity (n=20) were also assessed. We identified 40 patients (33%) with high VE/VCO(2) (ie, >34.0). During follow-up (49+/-22 months, >3 years in all survivors), 34 patients died (3-year survival 81%). High VE/VCO(2) (hazard ratio 4.3, P<0.0001) but not peak f1.gif" BORDER="0">O(2) (P=0.7) predicted mortality. In patients with high VE/VCO(2), 3-year survival was 57%, compared with 93% in patients with normal VE/VCO(2) P<0.0001). Patients with high VE/VCO(2) demonstrated impaired reflex control, as evidenced by augmented peripheral (P=0.01) and central (P=0.0006) chemosensitivity, depressed low-frequency component of heart rate variability (P<0.0001) and baroreflex sensitivity (P=0.03), and overactive ergoreceptors (P=0.003) compared with patients with normal VE/VCO(2). CONCLUSIONS: In CHF patients with preserved exercise capacity, enhanced ventilatory response to exercise is a simple marker of a widespread derangement of cardiovascular reflex control; it predicts poor prognosis, which VO(2) does not.

Chemosensitivity in chronic heart failure.

Augmented peripheral and central chemoreceptor sensitivity has recently been demonstrated in both experimental and clinical settings of chronic heart failure (CHF). As a result of the effects of chemoreflexes on the respiratory, circulatory and neurohormonal systems, changes in their activity may account for several pathophysiological features of CHF--predominantly augmented ventilation, abnormal cyclic respiratory pattern and sympathetic overactivity. Although the precise underlying mechanisms are not known, a heightened chemoreflex drive may constitute an ominous sign in CHF. Patients with abnormally elevated chemosensitivity demonstrate an augmented ventilatory response to exercise, a severely impaired autonomic regulation and suppression of baroreceptor function, and a higher prevalence of ventricular arrhythmias. All these factors may unfavorably influence the prognosis of CHF. In fact, we have recently confirmed in a group of patients with advanced CHF that high peripheral chemosensitivity is an independent predictor of death. New therapies are needed in CHF to improve prognosis and quality of life. Drugs, such as opiates, and oxygen administration have been shown to suppress chemosensitivity, which may further favorably influence exercise tolerance and modify periodic breathing in CHF patients. Treatment strategies targeted at peripheral and central chemoreceptors may be a promising option for further evaluation.

Oscillatory breathing patterns during wakefulness in patients with chronic heart failure: clinical implications and role of augmented peripheral chemosensitivity.

BACKGROUND: Oscillatory breathing patterns characterized by rises and falls in ventilation with apnea (Cheyne-Stokes respiration [CSR]) or without apnea (periodic breathing [PB]) commonly occur during the daytime in chronic heart failure (CHF). We have prospectively characterized patients with cyclical breathing in terms of clinical characteristics, indices of autonomic control, prognosis, and the role of peripheral chemosensitivity. METHODS AND RESULTS: To determine cyclical breathing pattern, power spectral analysis was applied to 30-minute recordings of respiration in 74 stable CHF patients. Analyses of heart rate variability and baroreflex sensitivity were used to assess autonomic balance. Peripheral chemosensitivity was assessed with the transient hypoxia method. We also determined whether the suppression of peripheral chemoreceptor activity (hyperoxia or dihydrocodeine) would influence the respiratory pattern. Cyclical respiration was found in 49 (66%) patients (22 [30%] CSR, 27 [36%] PB) and was associated with more advanced CHF symptoms, impaired autonomic balance, and increased chemosensitivity (0.80 and 0.75 versus 0.34 L. min(-1). %SaO(2)(-1), P<0.001, for CSR and PB versus normal breathing, respectively). Transient hyperoxia abolished oscillatory breathing in 7 of 8 patients. Dihydrocodeine administration decreased chemosensitivity by 42% (P=0.05), which correlated with improvement in respiratory pattern. Cyclical breathing predicted poor 2-year survival (relative risk 9.41, P<0.01, by Cox proportional hazards analysis), independent of peak oxygen consumption (P=0.04). CONCLUSIONS: An oscillatory breathing pattern during the daytime is a marker of impaired autonomic regulation and poor outcome. Augmented activity of peripheral chemoreceptors may be involved in the genesis of this respiratory pattern. Modulation of peripheral chemosensitivity can reduce or abolish abnormal respiratory patterns and may be an option in the management of CHF patients with oscillatory breathing.

The impact of cachexia on cardiorespiratory reflex control in chronic heart failure.

BACKGROUND: The mechanism of persistent neurohormonal and cardiorespiratory reflex abnormalities in chronic heart failure remain unclear. Also, why chronic heart failure patients who develop cachexia demonstrate a particularly abnormal neurohormonal profile and have a high risk of death is not known. Impaired reflex control within the cardiac and respiratory systems, and abnormal heart rate variability have both been linked to a poor outcome. Muscle reflexes may contribute to persistent neurohormonal overactivity in wasted patients. Thus, we hypothesized that patients with cardiac cachexia might exhibit particularly profound abnormalities in cardiorespiratory reflexes and heart ratevariability. METHODS AND RESULTS: We investigated 39 chronic heart failure patients: 13 with cardiac cachexia (non-intentional, non-oedematous, documented weight loss of >7.5% of previous normal weight over more than 6 months), and 26 non-cachectic chronic heart failure patients matched according to the severity of chronic heart failure (all men, mean age: 59 vs 60 years, NYHA functional class: 2.6 vs 2.5, peak O(2)consumption: 16.2 vs 16.8 ml. kg(-1). min(-1), left ventricular ejection fraction: 23 vs 24%, all P>0.2 for cachectic vs non-cachectic). In the assessment of the cardiorespiratory reflex control we investigated: cardiac sympathovagal balance (using spectral analysis of heart rate variability to derive low (LF, 0. 04-0.15Hz) and high frequency (HF, 0.15-0.4Hz) components), baroreflex sensitivity (using the phenylephrine method), and peripheral chemosensitivity (using the transient hypoxic method). There was a severely abnormal pattern of cardiorespiratory reflex control in patients with cachexia compared with non-cachectic patients. The former group exhibited severely impaired autonomic reflex control, characterized by an abnormal profile of heart rate variability (reduced LF component), and depressed baroreflex sensitivity (P=0.0001 and P=0.02, respectively, vs non-cachectics). Patients with cachexia also demonstrated an increased peripheral chemosensitivity (0.91 vs0.46 l. min(-1). %SaO(2)(-1), P<0.001, cachectic vs non-cachectic, respectively). In the correlation analyses the degree of impairment in the reflex control was more closely related to wasting, and to the level of neurohormonal activation (as measured by the levels of epinephrine and norepinephrine) than to conventional markers of the severity of heart failure. CONCLUSIONS: Chronic heart failure patients who developed cardiac cachexia demonstrate an abnormal reflex control within the cardiovascular and respiratory systems. The nature of the link between this phenomenon and hormonal changes and the poor prognosis of cachectic chronic heart failure patients warrants further investigation.

A neural link to explain the "muscle hypothesis" of exercise intolerance in chronic heart failure.

BACKGROUND: In chronic heart failure the cause of exercise limitation is still unclear: ergoreceptors, muscle afferents sensitive to exercise metabolites, are proposed as a neural link between muscular abnormalities and the limited exercise responses in this syndrome. METHODS: In 92 stable patients with heart failure (34 in New York Heart Association class I, 27 in class II, and 31 in class III) and 28 age-matched normal controls, we assessed exercise tolerance (maximal upright bicycle) and ergoreflex activity (2 dynamic hand grips: one control and one followed by 3 minutes of local circulatory occlusion to isolate the ergoreflex component by metabolite trapping). RESULTS: Patients, with respect to the controls, showed reduced exercise tolerance (peak VO2: 20 vs 33 mL/kg/min), increased ergoreflex effects on ventilation (9 vs 4 L/min), systolic pressure (37 vs 13 mm Hg), and leg vascular resistance (45 vs 22 units) (all P <.005); with the progression of the symptoms, a progressive increase in ergoreflex contribution to the ventilatory response to exercise was observed. The indexes of exercise limitation during arm and leg exercise (ie, peak VO 2, V/VCO2 slope) correlated highly with the ergoreflex contribution to ventilatory response during handgrip test ( r

Effects of amiodarone on the P-wave triggered signal-averaged electrocardiogram in patients with paroxysmal atrial fibrillation and coronary artery disease.

The effects of a 6-week treatment with amiodarone on the P-wave triggered signal-averaged electrocardiogram in patients with paroxysmal atrial fibrillation and coronary artery disease have been studied. Amiodarone favorably influences P-wave triggered signal-averaged electrocardiographic parameters, predominantly in patients in whom amiodarone is effective in preventing paroxysmal atrial fibrillation.

[Recording of atrial and ventricular signal averaged ECGs in patients with mitral valve prolapse syndrome]. / Rejestracja usrednionego sygnalu przedsionkowego i komorowego u chorych z wypadaniem platka zastawki mitralnej.

The aim of the study was to assess the time-domain parameters of atrial signal-averaged ECG (ASAECG) and ventricular signal-averaged ECG (SAECG) in patients with mitral valve prolapse (MVP) and healthy ones. Fifty patients with MVP (15 men, 35 women, mean age--37.1 +/- 8.9 years) and 50 healthy controls (36 men, 14 women, mean age 38.2 +/- 4.7 years) were studied). The following time-domain parameters of ASAECG were analysed: the root mean square voltage of the terminal 10, 20, 30 ms of filtered P wave (RMS10, 20, 30) and the total duration of filtered P wave (PWD). The atrial late potentials (ALP) were defined as the presence: RMS10 < 4 microV i PWD > 123 ms. As the time-domain parameters of SAECG we analysed: the root mean square voltage of the terminal 40, 50 ms of the filtered QRS (RMS 40, 50), the total filtered QRS duration (t-QRS) and the low-amplitude signal duration < 40 microV in the terminal QRS (LPD). The ventricular late potentials (VLP) were defined as the presence of at least two of the following criteria: t-QRS > 114 ms, RMS 40 < 20 microV i LPD > 38 ms. There was no difference in the time-domain parameters of ASAECG between patients with MVP and controls: RMS 10: 4.5 +/- 1.8 microV vs 4.8 +/- 1.9 microV, RMS 20: 6.3 +/- 2.2 microV vs 6.1 +/- 2.2 microV, RMS 30: 8.3 +/- 2.5 microV vs 7.1 +/- 2.7 microV and PWD 113 +/- 11.7 ms vs 116 +/- 15.2 ms, respectively. Three patients with MVP (6%) and 5 controls (10%) revealed ALP. THE time-domain parameters of SAECG did not differ in patients with MVP and controls: RMS 40: 40.2 +/- 29.1, microV vs 35.5 +/- 18.2 microV, RMS 50: 68.2 +/- 40.1 microV vs 64.4 +/- 33.6 microV and t-QRS-101.4 +/- 10.7 ms vs 101.8 +/- 10.9 ms i LPD--28.7 +/- 10.0 ms vs 28.3 +/- 10.0 ms, respectively. VLP were found in 7 patients with MVP (14%) and 5 controls (10%). Our findings suggest that time-domain parameters of ASAECG and SAECG could not differentiate patients with MVP and healthy ones. Moreover, the presence of ALP and VLP in MVP group did not correlate with supraventricular and ventricular arrhythmias recorded on ambulatory ECG.

Ventilatory response to exercise correlates with impaired heart rate variability in patients with chronic congestive heart failure.

In chronic congestive heart failure (CHF) an overactivity of muscle ergoreceptors and peripheral chemoreceptors may lead to an increased ventilatory response to exercise and contribute to the autonomic imbalance. The analysis of heart rate variability (HRV), which is a reliable method of studying autonomic regulations within the cardiovascular system, showed depressed HRV indexes in CHF, but predictors of abnormal HRV pattern in CHF remain controversial. Considering a common mechanism involved in generation of both abnormal ventilation and autonomic dysfunction in CHF, we hypothesized that impaired ventilation may be better than other variables of CHF severity in determining HRV parameters. Seventy-two patients with CHF (57+/-9 years, ejection fraction: 28+/-11%) underwent cardiopulmonary exercise testing; the relation between ventilation and carbon dioxide production (VE/VCO2) was used as an index of the ventilatory response to exercise. Time and frequency-domain measurements of HRV were derived from 24-hour electrocardiographic monitoring. Patients had reduced exercise tolerance with abnormal ventilatory response (peak oxygen consumption [VO2max]: 17.8+/-5.5 ml/kg/min, VE/VCO2: 36.0+/-9.8). Correlations were found between HRV measures and etiology, New York Heart Association (NYHA) functional class, and VO2max, but the strongest relation was observed for VE/VCO2 slope (r values from -0.33 to -0.65, p <0.01). In the multiple regression analysis only VE/VCO2 was found to correlate independently with all HRV measurements. To investigate the role of peripheral chemoreceptor overactivity as the mechanism of autonomic imbalance and the increased ventilatory response to exercise, we assessed peripheral chemosensitivity in 22 patients (mean value of peripheral chemosensitivity: 0.62+/-0.34 L/min/%SaO2, significantly higher than in normal controls, mean value: 0.29+/-0.20 L/min/%SaO2 in our laboratory). The activity of the peripheral chemoreflex inversely correlated with all parameters of HRV. Increased ventilatory response to exercise correlated with depressed HRV measures in patients with CHF better than other clinical variables. An important role of the increased peripheral chemosensitivity in this relation may be relevant, being also a potential link between functional severity and sympathovagal imbalance in CHF.

[The influence of ischemia provoked by dobutamine and exercise on presence of late potentials in patients after myocardial infarction]. / Wplyw przejsciowego niedokrwienia prowokowanego testem dobutaminowym i wysilkowym na obecnosc póznych potencjalów komorowych u chorych po zawale serca.

UNLABELLED: The aim of this study was to examine the influence of transient exercise- and dobutamine-induced myocardial ischemia on time domain parameters of signal-averaged ECG (SAECG) and presence of late potentials (LP) in patients after myocardial infarction (MI). The investigation covered 85 patients after healing of MI, divided into two groups. Group I (24 males and 2 females, mean age 56.8 +/- 6.4 yrs) had exercise-induced ischemia and group II consisted of 59 patients (51 males and 8 females, mean age 58.3 +/- 8.5 years) with ischemia provoked by the intravenous dobutamine stress-testing. In each patient 2-D echocardiography, 24-h ambulatory Holter ECG, coronary arteriography were performed before stress testing. The ischemia was proven by using Tc-99m MIBI myocardial perfusion and standard 12-lead ECG monitoring. Recordings of SAECG were registered at rest and during ischemia under influence of stress-testing. The following time-domain parameters of SAECG were analysed: the root-mean-square voltage of the last 40 and 50 ms of the filtered QRS complex (RMS40, 50), total time duration of filtered QRS (t-QRS) and duration of signal lower than 40 muV (LPD). LP were detected when two or three of following criteria's had been registered: RMS 40 < 20 muV, t-QRS > 114ms, LPD > 38s. There was no statistically significant differences in all time domain parameters of SAECG between records at the baseline and during ischemia in each study group. At the baseline LP have been registered in 11.5% and in 15% patients, respectively of group I and group II. On the top of ischemia during treadmill exercise stress-testing LP have been recorded in 27% subjects. Under influence of dobutamine-provoked ischemia LP have been registered in 25% patients. CONCLUSIONS: Exercise- and dobutamine-induced ischemia triggers development of LP in small grade in post-infarction patients.

[The influence of exercise and dobutamine-induced ischemia on the presence of late potentials in patients after myocardial infarction]. / Wplyw przejsciowego niedokrwienia mienia serca prowokowanego testem dobutaminowym i wysilkowym na obecnosc póznch potencjalów komorowych u chorych po zawale serca.

UNLABELLED: The aim of this study was to examine the influence of transient exercise- and dobutamine-induced myocardial ischemia on time domain parameters of signal-averaged ECG (SAECG) and presence of late potentials (LP) in patients after myocardial infarction (MI). The investigation covered 85 patients after healing of MI, divided into two groups. Group I (24 males and 2 females, mean age 56.8 +/- 6.4 yrs) had exercise-induced ischemia and group II consisted of 59 patients (51 males and 8 females, mean age 58.3 +/- 8.5 years) with ischemia provoked by the intravenous dobutamine stress-testing. In each patient 2-D echocardiography, 24-h ambulatory Holter ECG, coronary arteriography were performed before stress testing. The ischemia was proven by using Tc-99m. MIBI myocardial perfusion and standard 12-lead ECG monitoring. Recordings of SAECG were registered at rest and during ischemia under influence of stress-testing. The following time-domain parameters of SAECG were analysed: the root-mean-square voltage of the last 40 and 50 ms of the filters QRS complex (RMS40, 50), total time duration of filtered QRS (t-QRS) and duration of signals lower than 40 microV (LPD). LP were detected when two or three of following criterias had been registered: RMS 40 < 20 microV, t-QRS > 114 ms, LPD > 38 s. There was no statistically significant differences in all time domain parameters of SAECG between records at the baseline and during ischemia in each study group. At the baseline LP have been registered in 11.5% and in 15% patients, respectively of group I and group II. On the top of ischemia during treadmill exercise stress-testing LP have been recorded in 27% subjects. Under influence of dobutamine-provoked ischemia LP have been registers in 25% patients. CONCLUSION: Exercise- and dobutamine-induced ischemia triggers development of LP in small grade in post-infarction patients.

Depressed heart rate variability as an independent predictor of death in chronic congestive heart failure secondary to ischemic or idiopathic dilated cardiomyopathy.

After acute myocardial infarction, depressed heart rate variability (HRV) has been proven to be a powerful independent predictor of a poor outcome. Although patients with chronic congestive heart failure (CHF) have also markedly impaired HRV, the prognostic value of HRV analysis in these patients remains unknown. The aim of this study was to investigate whether HRV parameters could predict survival in 102 consecutive patients with moderate to severe CHF (90 men, mean age 58 years, New York Heart Association [NYHA] class II to IV, CHF due to idiopathic dilated cardiomyopathy in 24 patients and ischemic heart disease in 78 patients, ejection fraction [EF], 26%; peak oxygen consumption, 16.9 ml/kg/min) after exclusion of patients in atrial fibrilation with diabetes or with chronic renal failure. In the prognostic analysis (Cox proportional-hazards model, Kaplan-Meier survival analysis), the following factors were investigated: age, CHF etiology, NYHA class, EF, peak oxygen consumption, presence of ventricular tachycardia on Holter monitoring, and HRV measures derived from 24-hour electrocardiography monitoring, calculated in the time (standard deviation of all normal RR intervals [SDNN], standard deviation of 5-minute RR intervals [SDANN], mean of all 5-minute standard deviations of RR intervals [SD], root-mean-square of difference of successive RR intervals [rMSSD], and percentage of adjacent RR intervals >50 ms different [pNN50]) and frequency domain (total power [TP], power within low-frequency band [LF], and power within high-frequency band [HF]). During follow-up of 584 +/- 405 days (365 days in all who survived), 19 patients (19%) died (mean time to death: 307 +/- 315 days, range 3 to 989). Cox's univariate analysis identified the following factors to be predictors of death: NYHA (p = 0.003), peak oxygen consumption (p = 0.01), EF (p = 0.02), ventricular tachycardia on Holter monitoring (p = 0.05), and among HRV measures: SDNN (p = 0.004), SDANN (p = 0.003), SD (p = 0.02), and LF (p = 0.003). In multivariate analysis, HRV parameters (SDNN, SDANN, LF) were found to predict survival independently of NYHA functional class, EF, peak oxygen consumption, and ventricular tachycardia on Holter monitoring. The Kaplan-Meier survival curves revealed SDNN < 100 ms to be a useful risk factor; 1-year survival in patients with SDNN < 100 ms was 78% when compared with 95% in those with SDNN > 100 ms (p = 0.008). The coexistence of SDNN < 100 ms and a peak oxygen consumption < 14 ml/kg/min allowed identification of a group of 18 patients with a particularly poor prognosis (1-year survival 63% vs 94% in the remaining patients, p <0.001). We conclude that depressed HRV on 24-hour ambulatory electrocardiography monitoring is an independent risk factor for a poor prognosis in patients with CHF. Whether analysis of HRV could be recommended in the risk stratification for better management of patients with CHF needs further investigation.

[The effect of long term use of amiodarone hydrochloride on time and frequency domain parameters of signal averaged electrocardiogram in patients with ischemia heart disease]. / Wplyw przewlekle stosowanego chlorowodorku amiodaronu na parametry czasowe i czestotliwosc elektrokardiogramu wysokiego wzmocnienia u chorych na chorobe niedokrwienna serca.

The aim of this study was to assess the influence of amiodarone hydrochloride on time- and frequency-domain parameters of signal-averaged electrocardiogram (SAECG) in patients with ischaemic heart disease (IHD). The study population consisted of 33 patients (18 female and 15 male), mean age 59.2 +/- 7.7. Amiodarone hydrochloride was orally used in the initial dose 600 mg/day for 10 days, and subsequently 200 mg/days for 6 weeks. Recording of SAECG and ambulatory Holter monitoring were made at baseline and in 10 day and after 6 weeks of therapy. The following time-domain parameters were analyzed: the root mean square voltage of the last 40 and 50 ms of the filtered QRS (RMS40 i RMS50), total time duration of filtered QRS (t-QRS) and duration of low amplitude signals < 40 microV in the terminal part of QRS (LPD). Late potentials (LP) were recognized when at least two from three criteria were fulfilled: 1) RMS40 < 20 microV, 2) t-QRS > 114 ms, 3) LPD > 38 ms. Frequency analysis of SAECG allowed to calculate the following parameters in logarithmic scale: energy spectrum > -60 dB (A) and decibel drop at 40Hz (Dd) and also in linear scale: area ratio 20-50/0-20Hz (Ar) and magnitude ratio (MR1-7). The values of RMS40 and RMS50 did not significantly change during amiodarone therapy. The obtained values of t-QRS were significantly longer after antiarrhythmic therapy, respectively 97.8 +/- 9.1 ms at the baseline, 102.1 +/- 10 ms after 10 days (p < 0.05), and 104.1 +/- 10.4 ms after 6 weeks (p < 0.005). Moreover the values of LPD did not significantly change after amiodarone treatment. At the baseline the presence of LP were observed in 3 (9%), after 10 days were recorded in 8 (24%), and after 6 weeks in 7 (22%) cases. Only in one case the LP were observed during the whole antiarrhythmic therapy. Moreover, amiodarone hydrochloride did not statistically significant change frequency-domain parameters in logarithmic scale and in linear scale.

[Significance of atrial signal-averaged electrocardiogram analysis in diagnosis of paroxysmal atrial fibrillation in patients with mitral valve prolapse syndrome]. / Znaczenie analizy usrednionego sygnalu przedsionkowego w diagnostyce napadowego migotania przedsionków u chorych z wypadaniem platka zastawki dwudzielnej.

The aim of this study was to assess the clinical usage of recording time-domain parameters of atrial signal-averaged electrocardiogram (ASAECG) in diagnosis of paroxysmal atrial fibrillation (PAF) of patients with mitral valve prolapse (MVP). 85 patients with MVP recognized by echocardiography were divided into two groups: group I (MVP-PAG/+/) 41 pts (15 male and 26 female) mean age 37.1 +/- 8.9 with previously electrocardiographically documented episode of PAF, group II (MVP-PAF/-/) 44 pts (20 male, 24 female) mean age 39.1 +/- 14.3 without PAF. The control group III consisted of 35 persons: 24 male and 11 female in mean age 37.7 +/- 6.2 without any cardiovascular diseases. All patients underwent additional investigations included: T3, T4, electrocardiography, exercise-test with moving "running track", 24-hours monitoring ECG with Holter's method and ASAECG recording. The following time-domain parameters of ASAECG were calculated: the root mean square voltage of the terminal 10, 20, 30 ms of the filtered P-wave (RMS 10, 20, 30) and total time duration of filtered P-wave (PWD). The adaptation of time-domain parameters of atrial signal-average in differential diagnostics of PAF during MVP has appeared as useless from clinical point of view.

[Clinical significance of atrial signal-averaged electrocardiogram in patients with electrically-induced paroxysmal atrial fibrillation]. / Znaczenie kliniczne rejestracji usrednionego sygnalu przedsionkowego u chorych z wystymulowanym migotaniem przedsionków.

UNLABELLED: The aim of this study was to assess the diagnostic possibilities of recording of time-domain parameters of atrial signal-averaged electrocardiogram (ASAECG) in patients with electrically-induced paroxysmal atrial fibrillation (PAF). The investigation was done in 53 patients (34 male and 19 female) mean age 47.6 +/- 13.1 with electrically induced sustained PAF- > 30 sec (group I). As a controls were forty patients (28 male and 12 female) mean age 46.2 +/- 15.3 (group II). The following time-domain parameters of ASAECG were calculated: the root mean square voltage of the terminal 10,20,30 ms of the filtered P-wave (RMS10,20,30) and total duration of filtered P-wave (PWD) and also time duration of P-wave from Frank's leads X,Y,Z (XP,YP,ZP). The values of RMS10,20,30 were statistically significant lower in patients with PAF than in controls, respectively RMS10: 3.9 +/- 1.4 microV vs 5.4 +/- 2.3 microV, p < 0.005, RMS20: 5.3 +/- 2 microV vs 6.8 +/- 2.2 microV, p < 0.001 and RMS30: 6.8 +/- 2.1 microV vs 7.4 +/- 3.6 microV, p < 0.05. Also the values of PWD were significantly longer in group I: 121 +/- 14.6 ms than in group II: 113.9 +/- 13.5 ms, 1 p < 0.02. Analysing the values of XP,YP,ZP it's occurred that only YP in PAF patients was statistically longer than in control, respectively 111 +/- 14.8 ms vs 96.7 +/- 13.8 ms, p < 0.001. The best differential criteria for identification of patients with electrically-induced PAF were RMS20 < 6 microV and PWD > 118 ms and gave sensitivity of 52%, specificity of 79%, positive predictive value of 68%, negative of 66% and diagnostic accuracy of 67%. CONCLUSIONS: 1. In patients with electrically-induced PAF the lower values of RMS10,20,30 and longer PWD were detected. 2. The criteria for identification of patients with electrically-induced paroxysmal atrial fibrillation were the values of RMS20 < 6 microV and PWD > 118 ms.

[Transient myocardial ischemia in patients after myocardial infarction and late cell potentials]. / Przejsciowe niedokrwienie u chorych po zawale miesnia sercowego a pózne potencjaly komorowe.

The role of myocardial ischaemia in the development of late potentials (LP) on the signal-averaged ECG (SAECG) in patients with coronary artery disease (CAD) remains controversial. The aim of the study was to assess the influence of transient, scintigraphically-proven (Tc-99mMI-BI), exercise-induced ischaemia on the presence of LP in 51 pts with angiographically documented CAD. Patients were divided into 2 groups: 26 pts (mean age 53 +/- 7.7) without the history of myocardial infarction (MI) (Group I) and 25 pts (mean age 56.8 +/- 6.4) after MI (Group II). SAECG recording were performed at baseline (A) and during exercise-induced ischaemia (B). The following time-domain parameters of SAECG were analyzed: the root mean square voltage of the last 40 and 50 ms of filtered QRS (RMS40, 50), total time duration of filtered QRS (t0QRS) and time duration potentials < 40 microV (LPD). The ventricular late potentials (LP) were defined as the presence of at least two of the following criteria: tQRS > 114 ms, RMS 40 < 20 mV and LPD > 38 ms. We conclude that transient exercise-induced ischaemia increased the presence of LP in pts with CAD after MI but did not alter the arrhythmogenic substrate for LP in those without the history of MI.