Éva Tamás

Exercise Radionuclide Ventriculography for Predicting Post-Operative Left Ventricular Function in Chronic Aortic Regurgitation

OBJECTIVES Ejection fraction (EF) reaction upon exercise by radionuclide ventriculography and standard echocardiographic parameters was evaluated as predictors for post-operative left ventricular (LV) function in chronic aortic regurgitation (AR). BACKGROUND The optimal timing of surgery for chronic AR is when the left ventricle is still compensating for the volume and pressure overload without irreversible dysfunction. For asymptomatic patients when EF is normal and LV diameters are borderline, exercise testing is recommended by present guidelines. However, only a limited number of studies have been performed, and data are scarce on this subject. METHODS Radionuclide ventriculography with multiple gated acquisition at rest and during exercise was performed in 29 consecutive patients with severe chronic aortic regurgitation pre-operatively and 6 months post-operatively. Patient subgroups were formed based on pre-operative EF exercise response (DeltaEF) and were categorized as decreasing (DeltaEF <-5%), unaltered (-5% <or= DeltaEF <or= 5%), and increasing (DeltaEF > 5%). A 5% or higher increase was considered normal. The LV diameters and mass were measured by echocardiography. RESULTS Pre-operative LV diameters were markedly elevated before surgery and diminished significantly after surgery. Left ventricular diameters, LV mass, EF at rest (EF(rest)), and EF change from rest to exercise (DeltaEF) were independent of New York Heart Association functional class. Pre-operative end-diastolic diameter proved to be a predictor for pre- and post-operative DeltaEF (p = 0.003; p = 0.04) but not for the nature of the exercise response post-operatively. Patients with decreasing and unaltered EF pre-operatively presented a significantly higher but still abnormal DeltaEF post-operatively. Those with increasing EF pre-operatively had a similar response and a normal DeltaEF post-operatively. Pre-operative DeltaEF was not only a predictor for post-operative DeltaEF (p = 0.02) but also classified patients into post-operative subgroups (EF decreasing, p = 0.03; unaltered, p = 0.02; increasing, p = 0.0008). CONCLUSIONS An abnormal EF response to exercise may also occur in patients who do not fulfill criteria for surgery based on LV dimensions or EF. A follow-up of exercise LV function and adjusting the timing of surgery according to the nature of exercise response could, therefore, be beneficial.

Differences in recovery of left and right ventricular function following aortic valve interventions: A longitudinal echocardiographic study in patients undergoing surgical, transapical or transfemoral aortic valve implantation

To evaluate longitudinal left and right ventricular function (LVF and RVF) after transcatheter aortic valve implantation (TAVI) as compared to surgical aortic valve replacement (SAVR) and LVF and RVF after TAVI by the transfemoral (TF) or transapical (TA) approach.

Preoperative Longitudinal Left Ventricular Function by Tissue Doppler Echocardiography at Rest and During Exercise Is Valuable in Timing of Aortic Valve Surgery in Male Aortic Regurgitation Patients

BACKGROUND The aim of this study was to evaluate if left ventricular (LV) systolic function by tissue Doppler echocardiography at rest and during exercise preoperatively could predict postoperative LV function and thereby be useful in the timing of aortic valve surgery in patients with severe aortic regurgitation. METHODS In 29 patients (median age, 59 years; interquartile range, 39-64 years), echocardiography, tissue Doppler echocardiography, and radionuclide ventriculography were performed preoperatively and postoperatively at rest and during supine bicycle exercise. RESULTS Preoperative ejection fraction (EF) was 62%. Patients formed two groups, with basal LV peak systolic velocity (PSV) 5.9 cm/s preoperatively as the cutoff value between low and high PSV. Preoperatively, patients with low PSV had lower PSV during exercise (P < .005), EF during exercise (P < .05), and atrioventricular plane displacement (AVPD) at rest (P < .005) and during exercise (P < .05) than those with high PSV. Postoperatively, patients with low PSV had smaller AVPD at rest (P < .05), AVPD during exercise (P < .01), and PSV during exercise (P < .01). CONCLUSION In patients with chronic aortic regurgitation with EFs and LV dimensions not fulfilling criteria for surgery according to guidelines, preoperative PSV and AVPD at rest and during exercise detected postoperative LV dysfunction.

Polycaprolactone-thiophene-conjugated carbon nanotube meshes as scaffolds for cardiac progenitor cells.

The myocardium is unable to regenerate itself after infarct, resulting in scarring and thinning of the heart wall. Our objective was to develop a patch to buttress and bypass the scarred area, while allowing regeneration by incorporated cardiac stem/progenitor cells (CPCs). Polycaprolactone (PCL) was fabricated as both sheets by solvent casting, and fibrous meshes by electrospinning, as potential patches, to determine the role of topology in proliferation and phenotypic changes to the CPCs. Thiophene-conjugated carbon nanotubes (T-CNTs) were incorporated to enhance the mechanical strength. We showed that freshly isolated CPCs from murine hearts neither attached nor spread on the PCL sheets, both with and without T-CNT. As electrospun meshes, however, both PCL and PCL/T-CNT supported CPC adhesion, proliferation, and differentiation. The incorporation of T-CNT into PCL resulted in a significant increase in mechanical strength but no morphological changes to the meshes. In turn, proliferation, but not differentiation, of CPCs into cardiomyocytes was enhanced in T-CNT containing meshes. We have shown that changing the topology of PCL, a known hydrophobic material, dramatically altered its properties, in this case, allowing CPCs to survive and differentiate. With further development, PCL/T-CNT meshes or similar patches may become a viable strategy to aid restoration of the postmyocardial infarction myocardium.

Female athlete's heart: Systolic and diastolic function related to circulatory dimensions

There are relatively few studies on female athletes examining cardiac size and function and how these measures relate to maximal oxygen uptake (VO2max). When determining sports eligibility, it is important to know what physiological adaptations and characteristics may be expected in female athletes, taking body and cardiac size into account. The purposes of this study were (a) to compare right and left heart dimensions and function in female endurance athletes (ATH) and in non‐athletic female controls of similar age (CON); and (b) to explore how these measures related to VO2max. Forty‐six ATH and 48 CON underwent a maximal bicycle exercise test and an echocardiographic examination at rest, including standard and color tissue Doppler investigation. All heart dimensions indexed for body size were larger in ATH (all P < 0.01). The diastolic mitral E/A ratio was 27% higher in ATH (P < 0.001) while systolic left and right atrio‐ventricular longitudinal displacement was 7% (P = 0.002) and 15% (P < 0.001) larger in ATH, respectively. Half (50.3%) of the variability in VO2max could be explained by left ventricular end‐diastolic volume. Our results could be useful in evaluating female endurance athletes with suspected cardiac disease and contribute to understanding differences between female athletes and non‐athletes.

Measurement of physical work capacity in patients with chronic aortic regurgitation: a potential improvement in patient management

Background:  Timing of surgery in aortic regurgitation (AR) is important. Exercise testing is recommended upon uncertainty about functional limitations but reports on cardiopulmonary exercise testing (CPET) in populations with pure chronic AR are scarce.

Decreased aerobic capacity 4 years after aortic valve replacement in male patients operated upon for chronic aortic regurgitation

Exercise testing is underutilized in patients with valve disease. We have previously found a low physical work capacity in patients with aortic regurgitation 6 months after aortic valve replacement (AVR). The aim of this study was to evaluate aerobic capacity in patients 4 years after AVR, to study how their peak oxygen uptake (peakVO2) had changed postoperatively over a longer period of time. Twenty‐one patients (all men, 52 ± 13 years) who had previously undergone cardiopulmonary exercise testing (CPET) pre‐ and 6 months postoperatively underwent maximal exercise testing 49 ± 15 months postoperatively using an electrically braked bicycle ergometer. Breathing gases were analysed and the patients’ physical fitness levels categorized according to Åstrand’s and Wasserman’s classifications. Mean peakVO2 was 22·8 ± 5·1 ml × kg−1 × min−1 at the 49‐month follow‐up, which was lower than at the 6‐month follow‐up (25·6 ± 5·8 ml × kg−1 × min−1, P = 0·001). All but one patient presented with a physical fitness level below average using Åstrand’s classification, while 13 patients had a low physical capacity according to Wasserman’s classification. A significant decrease in peakVO2 was observed from six to 49 months postoperatively, and the decrease was larger than expected from the increased age of the patients. CPET could be helpful in timing aortic valve surgery and for the evaluation of need of physical activity as part of a rehabilitation programme.

Structure and function of the tricuspid and bicuspid regurgitant aortic valve: an echocardiographic study

OBJECTIVES The emerging new treatment options for aortic valve disease call for more sophisticated diagnostics. We aimed to describe the echocardiographic pathophysiology and characteristics of the purely regurgitant aortic valve in detail. METHODS Twenty-nine men, with chronic aortic regurgitation without concomitant heart disease referred for aortic valve intervention, underwent 2D transoesophageal echocardiographic (TEE) examination prior to surgery according to a previously published matrix. Measurements of the aortic valve apparatus in long and short axis view were made in systole and diastole and analysed off-line. The aortic valves were grouped as tricuspid (TAV) or bicuspid (BAV), and classified by regurgitation mechanism. RESULTS Twenty-four examinations were eligible for analysis of which 13 presented TAV and 11 BAV. The regurgitation mechanism was classified as dilatation of the aorta in 6 cases, as prolapse in 11 cases and as poor cusp tissue quality or quantity in 7 cases. The ventriculo-aortic junction (VAJ) and valve opening were closely related (TAV r = 0.5, BAV r = 0.73) but no correlation was found between the VAJ and the maximal sinus diameter (maxSiD) or the sinotubular junction (STJ). However, the STJ and maxSiD were significantly related (TAV vs BAV: systole r = 0.9, r = 0.8; diastole r = 0.9, r = 0.7), forming an entity. The conjoined BAV cusps were shorter than the anterior cusps when closed (P = 0.002); the inter-commissural distances of the cusps in the BAV group were significantly different (P = 0.001 resp. 0.03) in both systole and diastole. CONCLUSIONS The VAJ was independent of other aortic dimensions and should thereby be considered as a separate entity with influence on valve opening. The detailed 2D TEE measurements of this study add further important information to our knowledge about the function and echocardiographic anatomy of the pathological aortic valve and root either as a stand-alone examination or as a benchmark and complement to 3D echocardiography. This may have an impact on decisions regarding repairability of the native aortic valve.

Cardiac systolic regional function and synchrony in endurance trained and untrained females

Background Most studies on cardiac function in athletes describe overall heart function in predominately male participants. We aimed to compare segmental, regional and overall myocardial function and synchrony in female endurance athletes (ATH) and in age-matched sedentary females (CON). Methods In 46 ATH and 48 CON, echocardiography was used to measure peak longitudinal systolic strain and myocardial velocities in 12 left ventricular (LV) and 2 right ventricular (RV) segments. Regional and overall systolic function were calculated together with four indices of dyssynchrony. Results There were no differences in regional or overall LV systolic function between groups, or in any of the four dyssynchrony indices. Peak systolic velocity (s′) was higher in the RV of ATH than in CON (9.7±1.5 vs 8.7±1.5 cm/s, p=0.004), but not after indexing by cardiac length (p=0.331). Strain was similar in ATH and CON in 8 of 12 LV myocardial segments. In septum and anteroseptum, basal and mid-ventricular s′ was 6–7% and 17–19% higher in ATH than in CON (p<0.05), respectively, while s′ was 12% higher in CON in the basal LV lateral wall (p=0.013). After indexing by cardiac length, s′ was only higher in ATH in the mid-ventricular septum (p=0.041). Conclusions We found differences between trained and untrained females in segmental systolic myocardial function, but not in global measures of systolic function, including cardiac synchrony. These findings give new insights into cardiac adaptation to endurance training and could also be of use for sports cardiologists evaluating female athletes.

Intraoperative fires caused by alcoholic skin antiseptic and diathermy

UNLABELLED The authors describe two intraoperative fires during cardiac surgery. In both cases, in addition to the usual disinfection and isolation of the operating field, they wanted to reduce the infection hazard and to restore the partly ruined isolation by 70% alcoholic skin antiseptic solution. Soon after the disinfection, but before the evaporation of alcohol, diathermy was used and caused fire. In case of the first patient the fire spread over the isolation film and resulted second grade (5%) and third-grade (1%) burn injury which required plastic surgery. In the second case the patients beard caught fire causing second-grade (1%) burn that was treated locally. Despite these burn injuries both patients recovered after the heart surgery. These two intraoperative fires are 0.003-0.004% of all surgical procedures. CONCLUSION Fires during surgery are rare and might have serious consequences. They can be prevented by keeping the discipline of work and instructions of fire protection. The best way of prevention is regular education of all the staff (doctors, nurses, etc.) working in the operating theatre.