[Show abstract][Hide abstract] ABSTRACT: Sudden cardiac death mostly resulting from ventricular arrhythmia remains a cause of mortality in 19-30% of adults with congenital heart defects. Indications for implantable cardioverter-defibrillators in primary prophylaxis are still under research. Microvolt T wave alternans (MTWA) is one of the sudden cardiac death risk stratification methods. We determined the incidence of MTWA in these patients and its coincidence with ventricular arrhythmia as well as risk factors of ventricular arrhythmia/sudden cardiac death.
204 patients with complex congenital heart anomalies and 45 healthy volunteers underwent ambulatory ecg monitoring, a cardiopulmonary test, BNP assessment, echocardiography and an MTWA test. After excluding technically inadequate traces, the remaining 179 patients and 43 controls were classified into MTWA positive(+), negative(-) and indeterminate(ind) subgroups. Additionally, MTWA(+) and MTWA(ind) formed an 'abnormal' group, labeled. MTWA(non-). Results. Abnormal MTWA was observed more frequently in the study group compared to controls (59(33.0%)vs1(2.3%), p=0.000001). The MTWA(non-) group compared to MTWA(-) presented a higher number of males (61.0%vs37.5%, p=0.005), predominance of patients with NYHA>I (44.1%vs25.0%, p=0.007), pulmonary hypertension (16.9%vs0.8%, p=0.00007), lower blood saturation (97%(73-100)vs99%(69-100), p=0.0003), higher incidence of malignant arrhythmia (9(15.2%)vs(3(2.5%), p=0.003), lower peak oxygen consumption VO2(ml/kg/min) (23.1±5.9vs26.3±6.7, p=0.002), higher VE/VCO2slope (36.0(25-74)vs31.0(21-58), p=0.01). Multivariate logistic regression analysis proved that pulmonary hypertension (OR=13.7, p=0.03), male gender (OR=10.4, p=0.00002), VE/VCO2slope (OR=1.07, p=0.045) and VO2 (OR=0.89, p=0.04) increase the probability of MTWA(non-).
Abnormal MTWA is more frequent in adults with congenital heart diseases than in the healthy population. Its probability increases in patients demonstrating clinical findings conducive to lethal arrhythmia like heart failure and pulmonary hypertension.
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: Among adults with congenital heart diseases (CHD) evaluation of sudden cardiac death (SCD) risk remains a great challenge. Although microvolt T-wave alternans has been incorporated into SCD risk stratification algorithm, its role in adults with CHD still requires investigation. We sought to determine the incidence of MTWA in this specific group and its coincidence with ventricular arrhythmia (VA) and other clinical findings presumably associated with SCD. METHODS: A case--control study was performed in which 102 patients with CHD characterized by right ventricle pathology or single ventricle physiology (TGA, UVH, Ebstein's anomaly, ccTGA, Eisenmenger syndrome, DORV, CAT, unoperated ToF) were compared to 45 age- and sex-matched controls. All subjects underwent spectral MTWA test, ambulatory ecg monitoring, cardiopulmonary test, BNP assessment. After excluding technically inadequate traces, the remaining MTWA results were classified as positive(+), negative(-) and indeterminate(ind). Due to similar prognostic significance MTWA(+) and (ind) were combined into a common group labeled 'abnormal'. RESULTS: Abnormal MTWA was present more often in the study group, compared to controls (39.2% vs 2.3%, p = 0.00001). Sustained ventricular tachycardia (sVT) was observed more often among subjects with abnormal MTWA compared to MTWA(-): 19.4% vs 3.6%, p = 0.026. The patients with abnormal MTWA had a lower blood saturation (p = 0.047), more often were males (p = 0.031), had higher NYHA class (p = 0.04), worse cardiopulmonary parameters: %PeakVO2 (p = 0.034), %HRmax (p = 0.003). Factors proven to increase probability of abnormal MTWA on multivariate linear regression analysis were: sVT (OR = 20.7, p = 0.037) and male gender (OR = 15.9, p = 0.001); on univariate analysis: male gender (OR = 2.7, p = 0.021), presence of VA (OR = 2.6, p = 0.049), NYHA > I (OR = 2.06, p = 0.033), %HRmax (OR = 0.94, p = 0.005), %PeakVO2 (OR = 0.97, p = 0.042), VE/VCO2slope (OR = 1.05, p = 0.037). CONCLUSIONS: Abnormal MTWA occurs significantly more often in adults with the chosen forms of CHD than among healthy subjects. The probability of abnormal MTWA increases in patients with malignant VA, in males and among subjects with heart failure and cyanosis. MTWA might be of potential role in risk stratification for SCD in adults with CHD.
[Show abstract][Hide abstract] ABSTRACT: Cardiovascular events are the main cause of premature death after successful repair of aortic coarctation (CoA). The aim of this study was to assess the selected biochemical markers of atherosclerosis in normotensive CoA repaired patients and to establish its relation to ultrasound indexes of vascular pathology.
62 patients after CoA repair (37 males, age: 34.1 ± 1.4 yrs) and 20 control individuals (10 males, age: 34.8 ± 2.2 yrs) were enrolled in the study. The serum markers: asymmetric dimethylarginine (ADMA), nitrites/nitrates (NOx), high-sensitivity C-reactive protein (hsCRP), and following vascular parameters: flow-mediated dilatation (FMD), intima-media thickness (IMT) and pulse wave velocity (PWV) were analyzed.
33 CoA repaired patients were normotensive, and compared to controls, they presented higher serum ADMA concentrations (0.59 ± 0.04 umol/l vs. 0.46 ± 0.03 umol/l, p=0.035). An analysis of the vascular parameters revealed decreased FMD (4.75 ± 0.5%), NMD (11.86 ± 0.8%) and increased PWV (6.90 ± 0.2 m/s) values in the normotensive patients as compared with the control group (FMD: 8.6 ± 0.9%, p<0.001, NMD: 20.94 ± 1.7%, p<0.001; PWV: 5.49 ± 0.2, p=0.023). There were no differences in the serum levels of NOx, hsCRP as well as IMT values between normotensive patients and the control group. A multivariate regression analysis revealed that serum ADMA level was a factor independently associated with the FMD value (r=-0.334; p=0.031) in normotensive CoA repaired group.
Early biochemical and vascular indices of atherosclerosis such as increased serum ADMA concentration as well as impaired vasodilatation and increased arterial stiffness are observed in patients after CoA repair. Serum ADMA is a strong predictor of endothelial dysfunction in patients with CoA repair.
International journal of cardiology 02/2011; 158(3):364-9. · 6.18 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Patients after successful repair of coarctation of aorta (CoAo) are at risk of hypertension at rest and associated end-organ damage. The aim of the study was to assess arterial stiffness and function in adults after coarctation repair in relation to descending aorta (AoD) residual coarctation and patient's age at operation.
85 patients after CoAo repair (53 males) aged 34.6 ± 10.3 years; median age at operation 0.9 ± 8.2 years. The control group-30 individuals (18 males) at mean age 33.6 ± 8.2 years. The following central parameters: augmentation pressure (AP) and augmentation index (AI) as well as peripheral vascular parameters: flow-mediated dilatation (FMD), nitroglycerin-mediated vasodilatation (NMD), intima-media thickness (IMT) and pulse wave velocity (PWV) were measured.
47 CoAo-repaired patients were normotensive, and compared to control, they presented higher values of central parameters AP (7.3 ± 4.6 vs. 4.4 ± 3.6 mmHg; p = 0.002) and AI (18.6 ± 10.4 vs. 13.5 ± 4.3%; p = 0.03); as well as the increased PWV (6.8 ± 1.2 vs. 5.4 ± 0.9 m/s; p = 0.003), while IMT was comparable (0.53 ± 0.01 vs. 0.51 ± 0.01 mm; p = 0.06). The vasodilatation was impaired in the normotensive patients: FMD (4.8 ± 2.8 vs. 8.5 ± 2.3%; p = 0.00003) and NMD (11.3 ± 4.6 vs. 19.8 ± 7.2%; p = 0.00001). The comparison of recoarctation (46, 54%) to non-recoarctation (39, 46%) patients did not reveal any significant differences in resting systolic and diastolic pressures, as well as the values of AI and the peripheral vascular parameters; the value of AP was higher in the recoarctation patients (10.5 ± 6.9 vs. 7.5 ± 4.1; p = 0.02) and correlated positively with the gradient across AoD (r = 0.295, p = 0.01). There was no significant linear correlation between age at the time of surgery and any of peripheral arterial parameters.
Residual stenosis in AoD does not affect the arterial vasodilatation nor stiffness in patients after CoAo repair. Early operation has no impact on peripheral vascular remodeling or central pressure which supports the claim that coarctation of the aorta is a systemic vascular disorder which leads to progressive vascular and end-organ damage despite early correction.
Clinical Research in Cardiology 12/2010; 100(5):447-55. · 3.67 Impact Factor