The maximal oxygen uptake (V02 max) is a well-validated measure of cardiorespiratory function that is calculated during a maximal cardiopulmonary exercise test. V02 max enables physicians to objectively assess cardiopulmonary function to aid in decision-making for patients with CHD. A significant proportion of these patients however are unable to achieve a maximal exercise test, and as such, there is a need for reliable submaximal predictors of cardiorespiratory reserve.

The oxygen uptake efficiency slope represents a measure of how effectively oxygen is extracted from the lungs and taken into the body and can be calculated from a submaximal exercise test. Its reliability as a predictor of cardiorespiratory reserve has been validated in various patient populations, but there is limited evidence for its validity in adult patients with CHD.

Retrospective analysis of cardiopulmonary exercise test data in 238 consecutive patients with CHD who completed a maximal cardiopulmonary exercise test at our tertiary cardiology centre demonstrated a strong correlation between peak V02 and the oxygen uptake efficiency slope (0.936). A strong correlation with peak V02 was also demonstrated when oxygen uptake efficiency slope was calculated at ventilatory anaerobic threshold (OUESVAT), 75% (OUES75), and 90% (OUES90) of the test (0.833, 0.905, 0.927 respectively).

In adult patients with CHD who are unable to complete a maximal cardiopulmonary exercise test, the oxygen uptake efficiency slope is a reliable indicator of cardiopulmonary fitness which correlates strongly with peak V02 at or beyond the ventilatory anaerobic threshold. Further research is required to validate the findings in patients with less common anatomies and to assess the relationship between the oxygen uptake efficiency slope and mortality.

Cessation is the single most important decision smokers can make to improve their health. The aim of this study was to investigate the effects of a novel biomarker feedback intervention on smoking cessation. Participants (n = 14) were block matched into two groups – biomarker feedback and standard care (control) – and encouraged to stop smoking without the support of any pharmacological aids. All participants received standard smoking cessation advice and also had physiological measures collected during both rest and sub-maximal exercise testing at baseline, week 6 and week 12. The standard care group only received the smoking cessation advice as their intervention, whereas the biomarker feedback group were also given individual feedback in relation to their physiological results. Cessation rates were not significantly different between groups (p = 0.56) at week 12 follow-up; however, a calculation of odds ratios (OR) suggests that the biomarker feedback group was more likely to be successful when compared to standard care (OR = 4.5). Results suggest that targeting health motivations may positively influence cessation rates. Future research is needed to verify this result with a larger group.

Background: At present, a considerable number of patients survive who underwent an atrial switch operation for correction of complete transposition. Our study aimed to assess their long-term exercise performance and the serial evolution of cardiac function. Methods: We studied 22 patients 5 to 17 years after an atrial switch operation, and followed them serially for 3.5 ± 2 years after the first evaluation. Cardiorespiratory exercise function was assessed by analysis of gas exhange and by determination of the ventilatory anaerobic threshold. Echocardiography was performed on all evaluations. Results: All patients were in Class I of the classification of the New York Heart Association at all assessments. Ventilatory anaerobic threshold, however, was significantly lower than normal. It averaged 77.9% ± 13.7 of the normal mean value at the initial evaluation, and remained stable when re-evaluated later (76.2 ± 13.7%). At the initial study, the increase in oxygen uptake during graded exercise was below the 95% confidence limit in 6 of the patients, and was below this level in 10 patients at re-assessment. The subnormal values for oxygen uptake during submaximal exercise were associated with moderate to severe haemodynamic dysfunction. At echocardiography, 15 of 17 patients studied twice had mild to moderate right ventricular dilation and tricuspidregurgiation, which remained virtually the same at reasssesment. A stable sinus rhythm was initially present in 17 patients, and persisted in 15 patients during follow-up. Conclusion: At medium term follow-up, cardiorespiratory exercise performance remains stable in patients after atrial switch repair. Serial exercise testing appears useful, because in individual patients in the present study, a decreasing exercise tolerance correlated with development of haemodynamic sequels.

Echocardiographic measures of ventricular function during exercise may prove useful in assessing myocardial health. This study examined test–retest reproducibility of measurements of Doppler mitral flow velocity (E-wave) and myocardial tissue Doppler imaging (E′-, S-waves) during a progressive maximal upright cycle test in 12 healthy lean adolescent males. Measurements were taken as subjects pedalled to exhaustion with 35 watt work increments in two separate trials. We observed no significant differences in mean values at rest, submaximal (70 watts) exercise, or maximal exercise for all three variables. Coefficients of variation at maximal exercise were 5.3%, 7.4%, and 8.1% for mitral E, tissue Doppler-S, and tissue Doppler-E′, respectively. These findings indicated acceptable levels of reproducibility of Doppler ultrasound techniques for assessing ventricular systolic and diastolic functional response to maximal exercise in young lean male subjects.

Digitized M-mode echocardiograms of left ventricular function were obtained in 34 patients subsequent to surgical repair of tetralogy of Fallot and in 34 healthy subjects at rest. In 16 patients and 16 controls, studies were also made during submaximal semisupine bicycle exercise. At rest, the peak ejection rate and fractional shortening were slightly reduced in the patients, whereas peak filling rate was comparable in patients and controls. Pulmonary regurgitation did not seem to influence left ventricular function. During exercise, however, peak filling rate was reduced in the patients compared to the healthy subjects. At peak exercise, the peak filling rates were 27.8±6.3 cm•s−1 and 34.1±3.4 cm•s−1 in patients and controls, respectively (p<0.01). No differences were found in heart rate, fractional shortening, peak ejection rate or blood pressures between patients and controls throughout the exercise test. When the subjects were subdivided by median age, the oldest patients had reduced normalized peak filling rates throughout the exercise test, whereas no differences were found between younger and older healthy subjects. Thus, it is suggested that the reduced left ventricular peak filling rate found during exercise is caused by subclinical myocardial dysfunction which seems to be related to myocardial protection at surgery and the period of follow-up.

The purpose of this study was to assess cardiorespiratory responses to submaximal exercise in patients with univentricular atrioventricular connection after the Fontan operation, and to evaluate whether changes occur during medium-term follow-up. Eighteen patients (age 12.1±5.5 years) underwent graded exercise test on a treadmill 2.3±1.4 year after the Fontan repair. Ventilatory gases were measured using breath-by-breath analysis. Results were compared to gender/age-matched controls. Twelve patients (age 14.2±5.4 years) were reevaluated 2.4±2.1 years after the first test. Aerobic exercise performance was subnormal in all patients during the first test. At the lowest level of exercise, the ventilatory threshold was already surpassed in 6/18 patients, while it was reduced in all other patients (p<0.001). All patients were in stable sinus rhythm throughout the test. Heart rate at all exercise levels was ±10% below normal (p<0.05). The respiratory frequency was increased at all exercise levels (p<0.001). The ventilatory equivalent for oxygen was increased (p<0.001), and the end-tidal tension of carbon dioxide was decreased (p<0.001). The ratio of physiological dead space/tidal volume was increased in all patients (p<0.001), while the normal decrease of this ratio during exercise was not observed. Upon reevaluation heart rate, respiratory rate, oxygen uptake, venti latory equivalent for oxygen, end-tidal carbon dioxide tension and physiological dead space did not change signifi cantly. Only a slight further decrease in ventilatory threshold was observed. Aerobic performance after the Fontan procedure ranges widely from just above resting metabolic rate to the lower limit of normal. Dyspnea during exercise is exacerbated by a decreased ventilatory threshold, increased physiological dead space, and decreased respir-atory efficiency. Cardiorespiratory response to exercise, nonetheless, remains relatively stable during medium-term follow-up.

We treated prospectively 14 patients with Eisenmenger's syndrome, with a mean age of 10 years, ranging from 3 to 18 years. Treatment continued for 12 months, and demonstrated a lasting symptomatic improvement, but no improvement in terms of mean saturation of oxygen over 24 hours. Exercise capacity, as judged by peak uptake of oxygen, worsened in the six patients able to perform a treadmill test. The symptomatic benefit from dual blockage of endothelin receptors in these patients may be due to mechanisms other than selective pulmonary vasodilatation alone.

Regular monitoring of the heart rate (HR):speed relationship may help evaluate response to training and aid in the early detection of problems. This relationship is normally determined using a treadmill or via a ridden test conducted outside on a track. Simple practical alternative methods to obtain this relationship without access to a treadmill or a track could be of value in the field. To evaluate whether the HR:speed relationship could be determined via an indoor ridden test or a lunge test, HR was monitored on two occasions at least 3 h apart, in 12 adult horses (mixed breed) in a familiar environment during a 5 or 7 m radius circle lunge (unridden) test (5LT or 7LT) and an incremental (ridden) test (RT) on the same day. The RT comprised two ridden laps of the perimeter of a 60 × 40 m indoor school at walk, three laps at trot, three at medium canter and four at fast canter (all on the right rein). The speed of each lap was recorded. The LT comprised lunging for 2 min on each rein at walk, trot and canter. Speed was determined from the number of laps completed and measurement of the distance travelled. HR and speed were highly correlated in both lunge and ridden tests (both r = 0.99 ± 0.01). V140 on the ridden test (5.2 ± 0.6 m s− 1) was significantly greater than on the pooled lunge test data (4.4 ± 0.6; P < 0.0001). There was a negative correlation between recovery HR at 2 min following either the LT or RT and V140 (P < 0.05). The slope of the HR versus speed relationship and V140 were not different between RT and 7LT, but were significantly different from those of the 5LT (P < 0.05). V140 was always lower on the lunge tests compared with the ridden test. This suggests that, in this study, lunging without a rider increased the metabolic demand above that for being ridden at a similar speed. V140 determined by the 7LT gave the closest approximation to the V140 determined by the RT. The HR:speed relationship can be obtained either from riding an incremental test in an indoor school or from an unridden lunge test.

Background: Health-related quality of life in adults with congenital cardiac disease appears to be impaired, but the determinants of this alteration remain largely unknown. The aim of our study was to examine the impact of arrhythmias on quality of life in patients late after the atrial redirection operation for transposition, or after complete correction of tetralogy of Fallot. Patients and methods: We enrolled 32 patients with transposition, and 35 patients with tetralogy of Fallot, in a prospective study. Quality of life was assessed using RAND-36 questionnaires. Quality of life data were compared with those of an age-matched control population. Patients underwent 24-hour and 7-day electrocardiographic recordings, echocardiography, and exercise testing. Results: Patients without arrhythmias had quality of life comparable to that of the general population. All 8 domains in the questionnaire showed scores 22 to 51 percent lower in 12 patients with atrial tachyarrhythmias, and/or sinus nodal dysfunction, requiring insertion of a pacemaker in comparison with 55 patients without arrhythmias. In patients with transposition, low scores were not only associated with arrhythmias, but also correlated with impaired exercise capacity. Conclusions: Atrial tachyarrhythmias, and sinus nodal dysfunction, requiring insertion of a pacemaker, were associated with impaired quality of life in adults late after atrial surgical correction of transposition or correction of tetralogy of Fallot.