Cardiorespiratory parameters of exercise capacity in a healthy Lithuanian population: the pilot study.

INTRODUCTION: The normative values of exercise capacity used for the interpretation of exercise testing results are influenced by a variety of internal and external factors specific to certain populations. Therefore, in clinical practice it is recommended that population-specific reference values be employed. Cardiorespiratory fitness norms have not yet been established for a healthy Lithuanian population over a wide age span. The purpose of the present study was to determine the main cardiorespiratory fitness parameters for healthy adults living in Lithuania and to compare these parameters with the reference values established for different foreign populations. METHODS: This was a cross-sectional, community-based study involving 168 healthy adults aged from 20 to 60 years who were randomly selected from the general population. All subjects performed a progressive incremental exercise test on the cycle ergometer. The main cardiorespiratory fitness parameters analysed were peak oxygen consumption (VO2peak), ventilatory anaerobic threshold, and peak heart rate (HRpeak). RESULTS: The average estimated VO2peak was 35.02 ± 7.37 mL.kg(-1).min(-1) for men and 28.27 ± 6.33 mL.kg(-1).min(-1) for women. According to the results presented by other authors, this parameter is approximately 9-22% lower compared to other populations in all age groups, with the exception of the 20-29 year old group who alone satisfied fair aerobic fitness criteria. The average age-related decline in VO2peak was 0.016 L.min(-1) per year for men and 0.011 L.min(-1) per year for women. However, age itself explained only 12-14% of the variance. After VO2peak was adjusted relative to body mass, the difference in the decline between men and women remained insignificant: VO2peak decrease was 0.34 mL.kg(-1).min(-1) per year for men (coefficient of determination R(2) 0.250) and 0.32 mL.kg(-1).min(-1) per year for women (R(2) 0.330). A decline in peak heart rate of approximately 9 beats per minute was observed in each following age decade, which was well explained by the advancing age (R(2) 0.512 for men and R(2) 0.484 for women). CONCLUSIONS: Cardiorespiratory fitness parameters estimated for healthy adults living in Lithuania appeared to be lower compared to different foreign populations, despite the relatively similar general trends in the age-related decline in exercise capacity. Exercise testing laboratories and rehabilitation clinics in Lithuania may use these results in clinical practice when evaluating patients' exercise capacity, or as a promotional tool for physical activity in the general public.

Age-dependent heterogeneity of familiar hypertrophic cardiomyopathy phenotype: a role of cardiovascular magnetic resonance.

In this case report, we present familiar hypertrophic cardiomyopathy with age-dependent heterogeneity of the disease phenotype among the members of one family who carry the same mutation of the myosin-binding protein C gene. Phenotypic heterogeneity is common in patients with familial forms of hypertrophic cardiomyopathy, both in clinical expression and outcome. Compared with other noninvasive cardiac imaging modalities, cardiovascular magnetic resonance provides an opportunity to more accurately characterize the varying phenotypic presentations of hypertrophic cardiomyopathy.

Non-invasive evaluation of myocardial reperfusion by transthoracic Doppler echocardiography and single-photon emission computed tomography in patients with anterior acute myocardial infarction.

BACKGROUND: The study was designed to evaluate whether the preserved coronary flow reserve (CFR) 72 hours after reperfused acute myocardial infarction (AMI) is associated with less microvascular dysfunction and is predictive of left ventricular (LV) functional recovery and the final infarct size at follow-up. METHODS: In our study, CFR was assessed by transthoracic Doppler echocardiography (TDE) in 44 patients after the successful percutaneous coronary intervention during the acute AMI phase. CFR was correlated with contractile reserve assessed by low-dose dobutamine echocardiography and with the total perfusion defect measured by single-photon emission computed tomography 72 hours after reperfusion and at 5 months follow-up. The ROC analysis was performed to determine test sensitivity and specificity based on CFR. Categorical data were compared by an χ² analysis, continuous variables were analysed with the independent Student's t test. In order to analyse correlation between CFR and the parameters of LV function and perfusion, the Pearson correlation analysis was conducted. The linear regression analysis was used to assess the relationship between CFR and myocardial contractility as well as the final infarct size. RESULTS: We estimated the CFR cut-off value of 1.75 as providing the maximal accuracy to distinguish between patients with preserved and impaired CFR during the acute AMI phase (sensitivity 91.7%, specificity 75%). Wall motion score index was better in the subgroup with preserved CFR as compared to the subgroup with reduced CFR: 1.74 (0.29) vs. 1.89 (0.17) (p < 0.001) during the acute phase and 1.47 (0.30) vs. 1.81 (0.20) (p < 0.001) at follow-up, respectively. LV ejection fraction was 47.78% (8.99) in preserved CFR group vs. 40.79% (7.25) in impaired CFR group (p = 0.007) 72 hours after reperfusion and 49.78% (8.70) vs. 40.36% (7.90) (p = 0.001) after 5 months at follow-up, respectively. The final infarct size was smaller in patients with preserved as compared to patients with reduced CFR: 5.26% (6.14) vs. 23.28% (12.19) (p < 0.001) at follow-up. CONCLUSION: The early measurement of CFR by TDE can be of high value for the assessment of successful reperfusion in AMI and can be used to predict LV functional recovery, myocardial viability and the final infarct size.

Patient education significantly improves quality of life, exercise capacity and BNP level in stable heart failure patients.

UNLABELLED: The aim of the study was to evaluate the impact of complex ambulatory education on quality of life, exercise capacity and B-type natriuretic peptide (BNP) level in chronic stable heart failure patients. MATERIAL AND METHODS: Heart failure patients in NYHA class II/III (n = 31) on optimal medical treatment were recruited from the outpatient department. The following data were evaluated before and 2 months after the patient education: quality of life (evaluated by the Minnesota questionnaire), peak exercise oxygen consumption (VO2) and BNP level. RESULTS: The mean general quality of life evaluation index (QoLES) decreased significantly in 2 months after the education (37.90 +/- 18.78 versus 49.39 +/- 17.86 prior to the education, P < 0.001), an improvement in quality of life. Peak exercise VO2 in 2 months after the tuition significantly increased (19.26 +/- 7.22 versus baseline 16.25 +/- 3.69 ml/kg/min; P = 0.013) as well as the anaerobic threshold (AT VO2 was 12.694 +/- 3.28 ml/kg/min versus baseline 11.197 +/- 2.47 ml/kg/min; P = 0.003). The indices reflecting external load also increased significantly: workload, duration of the exercise and METs. A significant proportion of the patients 2 months after the education moved to lower NYHA functional classes. Plasma BNP level decreased significantly in 2 months after the tuition: 224 +/- 340.36 versus baseline 348.41 +/- 471.99 ng/I; P = 0.023. CONCLUSIONS: Patient education with the emphasis on adherence, self-care management and physical training has a reliable positive impact on the quality of life, exercise capacity and plasma levels of B-type natriuretic peptide in the population of stable moderate HF patients.

Cardiovascular magnetic resonance imaging for detection of myocardial viability in chronic ischemic left ventricular dysfunction.

Chronic ischemic left ventricular dysfunction is present in number of clinical syndromes in which myocardial revascularization results in an improvement of left ventricular function, patients' functional class, and their survival. Coronary arteriography is of limited value in diagnosis of viability. Noninvasive testing, traditionally nuclear imaging, stress echocardiography and (stress) electrocardiography have been the clinical mainstays for assessing myocardial viability as well as to detect myocardial ischemia. However, cardiovascular magnetic resonance is a rapidly emerging noninvasive imaging technique, providing high-resolution images of the heart in any desired plane and without radiation. Rather than a single technique, cardiovascular magnetic resonance consists of several techniques that can be performed separately or in various combinations during a patient examination. Whereas, no single cardiovascular magnetic resonance technique has a perfect, or near perfect, sensitivity and specificity, therefore, a combination of various cardiovascular magnetic resonance techniques are needed for the assessment of myocardial viability. The aim of this review article is to summarize our current understanding of the concept of myocardial viability, to discuss the clinical value of cardiovascular magnetic resonance (in particular the different cardiovascular magnetic resonance techniques to assess viability) for the evaluation of patients with coronary artery disease and chronic left ventricular dysfunction and to present the current place of cardiovascular magnetic resonance among other techniques for the assessment of viable myocardium.

Is post-systolic motion the optimal ultrasound parameter to detect induced ischaemia during dobutamine stress echocardiography?

AIMS: Doppler myocardial imaging (DMI) has been suggested as a method of quantifying induced ischaemia during dobutamine stress echocardiography (DSE). The aim of the present study was to investigate both standard systolic and diastolic parameters, but more specifically to address the phenomenon of post-systolic motion (PSM) as a marker of acquired ischaemia during DSE using pulsed-wave DMI. METHODS AND RESULTS: We examined 60 patients without previous myocardial infarction who underwent DSE. Peak systolic, post-systolic, early and late diastolic velocities were measured at rest and during stress. Myocardial segments (n = 908) were divided into ISCHAEMIC and NON-ISCHAEMIC groups according to the presence of significant angiographic coronary stenosis. ISCHAEMIC segments (n = 357) compared with NON-ISCHAEMIC segments (n = 551) demonstrated a reduced increase of systolic velocity (8.0-12.7 vs 9.3-16.4 cm/s, P < 0.05), prominent PSM (5.8-8.3 vs 0.63-2.1 cm/s, P < 0.000001) and reduced early diastolic velocity (6.5-10.2 vs 7.9-13.2 cm/s, P < 0.04) during stress. The peak velocity of PSM was the most accurate index of induced ischaemia (sensitivity 73-100%, specificity 82-97%) compared to systolic and early diastolic velocities (sensitivity 52-77% and 63-68%, specificity 63-77% and 59-81%, respectively). CONCLUSION: PSM derived by pulsed-wave DMI during DSE was the most sensitive index of acquired ischaemia compared to other functional DMI indices.