Mechanisms of Exercise Capacity Improvement after Cardiac Rehabilitation Following Myocardial Infarction Assessed with Combined Stress Echocardiography and Cardiopulmonary Exercise Testing

Cardiac rehabilitation (CR) is indicated in all patients after acute myocardial infarction (AMI) to improve prognosis and exercise capacity (EC). Previous studies reported that up to a third of patients did not improve their EC after CR (non-responders). Our aim was to assess the cardiac and peripheral mechanisms of EC improvement after CR using combined exercise echocardiography and cardiopulmonary exercise testing (CPET-SE). The responders included patients with an improved EC assessed as a rise in peak oxygen uptake (VO2) ≥ 1 mL/kg/min. Peripheral oxygen extraction was calculated as arteriovenous oxygen difference (A-VO2Diff). Out of 41 patients (67% male, mean age 57.5 ± 10 years) after AMI with left ventricular ejection fraction (LVEF) ≥ 40%, 73% improved their EC. In responders, peak VO2 improved by 27% from 17.9 ± 5.2 mL/kg/min to 22.7 ± 5.1 mL/kg/min, p < 0.001, while non-responders had a non-significant 5% decrease in peak VO2. In the responder group, the peak exercise heart rate, early diastolic myocardial velocity at peak exercise, LVEF at rest and at peak exercise, and A-VO2Diff at peak exercise increased, the minute ventilation to carbon dioxide production slope decreased, but the stroke volume and cardiac index were unchanged after CR. Non-responders had no changes in assessed parameters. EC improvement after CR of patients with preserved LVEF after AMI is associated with an increased heart rate response and better peripheral oxygen extraction during exercise

L-arginina poprawia tolerancję wysiłku w niewydolności serca

Background: In congestive heart failure (CHF), endothelial dysfunction may contribute to impairment of exerciseinduced vasodilatation and decreased exercise capacity. We hypothesised that administration of L-arginine, a precursor of nitric oxide (NO) and postulated antioxidant, may improve endothelium - dependent vasodilatation and exercise capacity and also exert antioxidant activity.Aims: To investigate the effect of oral supplementation with L-arginine on exercise capacity and markers of oxidative stress in patients with mild to moderate CHF.Methods: The study had a randomised double-blind cross-over design. Twenty one patients with stable NYHA II-III CHF underwent three exercise tests: initially, after oral administration of L-arginine (9 g/day for 7 days) or placebo. Blood was sampled prior to each test for plasma lipid peroxides, reduced sulphydryl groups and leukocyte oxygen free radical production.Results: We found a higher prolongation of exercise duration time after L-arginine than after placebo (99±106 vs 70±99 s,

Profil lipidowy oznaczony w ciągu pierwszych 24 godzin zawału serca ma istotne znaczenie prognostyczne

Aims: A high level of total cholesterol and LDL-cholesterol disturbs the endothelial function. Thus it can be expected, that hypercholesterolaemia may unfavourably influence the course of the acute myocardial infarction. The aim of the study was to check whether patients with lipid levels above normal during the first hours of myocardial infarction have an unfavourable clinical outcome.Methods and results: The study group consisted of 348 patients (216 males, aged 65.7±12 years) with acute myocardial infarction hospitalized up to 24 hours after the onset of symptoms. Blood samples for lipid profile were taken on the first day of hospitalization, in the morning, while fasting. 109 (31%) patients had a complicated in-hospital course of infarction (i.e. death, recurrent ischaemia, serious arrhythmias and/or conduction disturbances, heart failure). The total cholesterol and LDL-cholesterol levels were higher in the patients with complicated than in the patients with uncomplicated clinical course of infarction: 243±40.7 vs 211.2±40.6 mg/dl,

Chronotropic Incompetence Limits Aerobic Exercise Capacity in Patients Taking Beta-Blockers: Real-Life Observation of Consecutive Patients

Background: Chronotropic incompetence in patients taking beta-blockers is associated with poor prognosis; however, its impact on exercise capacity (EC) remains unclear. Methods: We analyzed data from consecutive patients taking beta-blockers referred for cardiopulmonary exercise testing to assess EC. Chronotropic incompetence was defined as chronotropic index (CI) ≤ 62%. Results: Among 140 patients all taking beta-blockers (age 61 ± 9.7 years; 73% males), 64% with heart failure, chronotropic incompetence was present in 80.7%. EC assessed as peak oxygen uptake was lower in the group with chronotropic incompetence, 18.3 ± 5.7 vs. 24.0 ± 5.3 mL/kg/min, p < 0.001. EC correlated positively with CI (β = 0.14, p < 0.001) and male gender (β = 5.12, p < 0.001), and negatively with age (β = −0.17, p < 0.001) and presence of heart failure (β = −3.35, p < 0.001). Beta-blocker dose was not associated with EC. Partial correlation attributable to CI accounted for more than one-third of the variance in EC explained by the model (adjusted R2 = 59.8%). Conclusions: In patients taking beta-blockers, presence of chronotropic incompetence was associated with lower EC, regardless of the beta-blocker dose. CI accounted for more than one-third of EC variance explained by our model

Cardiopulmonary exercise testing in adult cardiology: expert opinion of the Working Group of Cardiac Rehabilitation and Exercise Physiology of the Polish Cardiac Society

ABSTRACT Cardiopulmonary exercise testing (CPET) is an important diagnostic tool in contemporary clinical practice. This document presents an expert opinion from the Working Group on Cardiac Rehabilitation and Exercise Physiology of the Polish Cardiac Society concerning the indications, performance technique, and interpretation of results for CPET in adult cardiology. CPET is an electrocardiographic exercise test expanded with exercise evaluation of ventilatory and gas exchange parameters. It allows for a global assessment of the exercise performance including the pulmonary, cardiovascular, hematopoietic, neuropsychological, and musculoskeletal systems. It provides a noninvasive dynamic evaluation during exercise and is a reference modality for exercise capacity assessment. Moreover, it allows the measurement of numerous prognostic parameters. It is useful in cardiology, pulmonology, oncology, perioperative assessment, rehabilitation as well as in sports medicine and in the evaluation of healthy people. This test not only helps to diagnose the causes of exercise intolerance but also supports the evaluation of the treatment. New opportunities are offered by combining CPET with imaging such as exercise stress echocardiography. These tests are complementary and synergistic in their diagnostic and prognostic strength

Efficacy and safety of oral l-arginine in acute myocardial infarction. Results of multicenter, randomized, double-blind, placebo-controlled ARAMI pilot trial

Aims: L-arginine is a substrate for nitric oxide (NO) synthesis in vascular endothelial cells. NO bioavailability is decreased during myocardial infarction (MI). It might be expected that administration of L-arginine may maintain NO production and alleviate the course of MI. The aim of the study was to assess safety and effects of treatment with L-arginine on the clinical course of MI.Methods and Results: 792 patients (mean age 64 years, 551 men) with ST segment elevation MI admitted within 24h after the onset of symptoms were randomized to oral L-arginine (3.0 t.i.d p.o. for 30 days) or placebo on top of routine therapy. The end point which was the composite of 30 day cardiovascular death, reinfarction, successful resuscitation, shock/pulmonary edema or recurrent myocardial ischemia occurred in 24% patients treated with L-arginine and 27% with placebo (OR 0.63, 95% CI 0.39-1.02, p=0.06). The end point was observed less frequently in 226 patients with hyperlipidemia (19 vs 31,

Sercowo‑płucne testy wysiłkowe w kardiologii dorosłych

Sercowo‑płucny test wysiłkowy (cardiopulmonary exercise testing – CPET) to ważne badanie wykorzystywane nie tylko w celach naukowych, ale również w codziennej praktyce klinicznej. Jest to elektrokardiograficzny test wysiłkowy rozszerzony o wysiłkową ocenę parametrów wentylacyjnych i wymiany gazowej. Badanie to, poprzez bezpośredni pomiar poboru tlenu, pozwala na dokładniejszą ocenę wydolności fizycznej niż elektrokardiograficzny test wysiłkowy. Umożliwia nie tylko diagnostykę przyczyn ograniczonej tolerancji wysiłku, ale również ocenę skuteczności stosowanego leczenia, w tym planowanie i ocenę efektów rehabilitacji kardiologicznej. Niniejszy dokument stanowi skróconą wersję stanowiska ekspertów Sekcji Rehabilitacji Kardiologicznej i Fizjologii Wysiłku Polskiego Towarzystwa Kardiologicznego (SRK i FW PTK) dotyczącego wykonywania i interpretacji wyników CPET u dorosłych. Omówiono w nim wskazania oraz podstawowe parametry wentylacyjne i wymiany gazowej wraz z ich interpretacją, a także zastosowanie CPET w różnych sytuacjach klinicznych: w różnicowaniu przyczyn duszności wysiłkowej, w niewydolności serca, wadach wrodzonych, kardiomiopatii przerostowej, nadciśnieniu płucnym, chorobie wieńcowej, u chorych z urządzeniami wszczepialnymi, w pulmonologii, onkologii, ocenie okołooperacyjnej, rehabilitacji kardiologicznej i sporcie. Oddzielny rozdział poświęcono perspektywom wykorzystania CPET w połączeniu z echokardiografią wysiłkową