Frauke Wenzelburger

Reduced left atrial function on exercise in patients with heart failure and normal ejection fraction

Aims The cardinal symptom of heart failure with a normal ejection fraction (HFNEF) is exertional dyspnoea. The authors hypothesised that failure of left atrial (LA) compensatory mechanism particularly on exercise contributes to the genesis of symptoms in HFNEF patients. Methods and Results Fifty HFNEF patients, 15 asymptomatic hypertensive subjects and 30 healthy controls underwent rest and submaximal exercise echocardiography. Rest and exercise systolic, early diastolic and late diastolic (Am) mitral annular velocities were assessed using colour tissue Doppler echocardiography. Left atrial functional reserve index was calculated. Am at rest was comparable between all three groups, but exercise Am was significantly lower in HFNEF compared with hypertensive subjects and healthy controls resulting in a lower LA functional reserve index (0.84 (1.34) vs 2.39 (1.27) and 1.81 (1.39), p<0.001). LA volume index was significantly higher in HFNEF patients (30.4 (9.2) vs 27.9 (6.3) and 23.2 (7.1) ml/m2, p=0.002). There was a significant correlation between Am on exercise with peak VO2 max (r=0.514, p<0.001) and E/Em on exercise (r=−0.547, p<0.001). Area under the receiver operating characteristic for Am on exercise was 0.768 (95% CI=0.660 to 0.877). Conclusion HFNEF patients have reduced LA function on exercise in addition to left ventricular systolic and diastolic dysfunctions. Reduced LA function probably contributes significantly to exercise intolerance and breathlessness in HFNEF patients.

Mitral annular plane systolic excursion on exercise: a simple diagnostic tool for heart failure with preserved ejection fraction.

Current guidelines for the diagnosis of heart failure with normal or preserved ejection fraction (HFpEF) are based on measurements at rest. However, in HFpEF ventricular dysfunction is more apparent on exercise. We hypothesized that Mitral annular plane systolic excursion (MAPSE) which is easy to acquire on exercise could be used to detect occult left ventricular (LV) impairment.

Abnormal left ventricular function occurs on exercise in well-treated hypertensive subjects with normal resting echocardiography

Objectives This study tests the hypothesis that patients with treated hypertension with well-controlled blood pressure, without ventricular hypertrophy and normal resting echocardiography, may have abnormalities of ventricular function that are apparent only on exercise and contribute to symptoms of exertional dyspnoea. Methods Patients with hypertension with well-controlled blood pressure on medication and normal baseline echocardiography underwent cardiopulmonary exercise testing to determine their peak oxygen consumption (Vo2max), followed by rest and submaxinal supine exercise echocardiography (standard, tissue Doppler and speckle tracking). Results 30 patients with treated hypertension with a history of exertional dyspnoea (mean age 71±8 years; 18 women) and 22 age-matched healthy controls (70±6 years; 16 women) had rest and exercise images of sufficient quality for analysis. Both groups had comparable standard echocardiographic findings at rest. On exercise, the patients had reduced systolic longitudinal function (reserve index 0.97±1.34 vs 2.32±1.24, p=0.001), delayed early untwisting (20.4±7.6 vs 30.6±7.8%, p=0.001) and reduced ventricular suction (velocity propagation 10.6±10.9 vs 24.5±12.2 m/s, p<0.001) compared with healthy controls, which correlated with significantly reduced Vo2max. Conclusion Patients with treated hypertension with normal resting echocardiography can have exercise limitation associated with widespread systolic and diastolic left ventricular dysfunction on exercise. Normal resting echocardiography does not preclude the presence of significant functional abnormalities on exercise that can contribute to symptoms.

Exercise-induced torsional dyssynchrony relates to impaired functional capacity in patients with heart failure and normal ejection fraction

Background Left ventricular (LV) systole and diastole are intimately dependent on myocardial torsion, which involves coupling between myocardial rotation (twisting in systole and untwisting in diastole) and longitudinal motion. Heart failure with normal ejection fraction (HFNEF) is known to involve exercise-induced wall motion abnormalities, but torsion on exercise has not been explored. We hypothesised that torsional dyssynchrony may also be involved and be exaggerated by exercise. Methods and Results 67 patients (age 73±7 years, 45 female) with HFNEF and 38 controls underwent cardiopulmonary exercise testing and echocardiography at rest and on supine exercise. Analysis of three plane motions was performed using speckle tracking and tissue Doppler imaging. Torsional dyssynchrony was quantified as the SD of the time to peak systolic motion (SDSM) (basal and apical rotation, longitudinal and radial displacement); the time difference between peak twist and peak longitudinal displacement (twist-longitudinal motion delay, TLMD) and the ratio of untwist to longitudinal extension (UT:LE). At rest, HFNEF patients had similar SDSM, TLMD and UT:LE compared with controls. Exercise was associated with significantly more dyssynchrony in the HFNEF patients (SDSM 38.8±27.6 ms vs 25.9±15.5 ms, p=0.02; TLMD 28.4±46.2 ms vs 2.9±31.2 ms, p=0.005 and UT:LE 10.4±15.3 vs 3.3±3.8, p=0.022). The SDSM correlated positively with LV wall thickness (r=0.31, p=0.015) and negatively with peak oxygen consumption (r=−0.299, p=0.01) and changes in stroke volume on exercise (r=−0.371, p=0.001). Conclusions HFNEF involves exercise-induced torsional dyssynchrony in systole and diastole, which relates to LV hypertrophy as well as exercise capacity.

Analysis of Platelet Function during Left Ventricular Support with the Incor and Excor System

Improvements in pump technology and the scarcity of donor organs have led to an increased use of mechanical assist devices, but the problem of thromboembolism has still not been solved. We report on our initial experience with sequentially analyzing platelet function in patients provided with the Incor left ventricular assist device (LVAD) and the Excor LVAD system. Thirteen patients 5 to 61 years old with acute or end-stage heart failure were included in a pilot study. Five of the 10 Incor patients underwent LVAD placement under emergency conditions, and 5 were electively scheduled for surgery. All 3 patients with an Excor device had been connected to an extracorporeal membrane oxygenation system prior to insertion of the device. An anticoagulation protocol including heparin, aspirin, and clopidogrel was employed, and the patients were closely monitored with a special platelet analyzing system that allows dose optimization for antiplatelet drugs. Initial platelet function was normal in only 2 patients (15%). During a follow-up period of 1770 days (cumulative >4.8 years), no early (<30 days) bleeding complications related to device implantation occurred. Late cerebral thromboembolic events were noted in 3 patients. One patient experienced severe stroke mandating neurosurgery during mechanical assist, and 1 patient experienced systemic embolism. The PAP platelet analyzer offers a cheap and reliable alternative to the more expensive thromboelastography method for adequately surveying the efficacy of aspirin and clopidogrel treatment, even if late thromboembolic events cannot be prevented.

008 Left ventricular hypertrophy is associated with intramural dyssynchrony on exercise in patients with heart failure and normal ejection fraction

Background The pathophysiology of heart failure with normal ejection fraction (HFNEF) is complex and not fully understood. We hypothesised that left ventricular hypertrophy (LVH) which is found in most patients with HFNEF might lead to intramural dyssynchrony and uncoupling of the complex 3-dimensional motion of the left ventricle (LV) particularly on exercise. Method 33 patients with the clinical diagnosis of HFNEF (age 69±11 years, 19 female, EF 60±7%) and LVH (according to American Society of Cardiology, female >95 g/m2, male 115 g/m2) underwent detailed 2D-echocardiography at rest and on supine exercise. They were compared to 41 clinically diagnosed HFNEF patients without LVH (age 73±8 years, 26 females, EF 61±7%) and 35 age-matched control subjects (age 71±7 years, 27 females, EF 63±7). All subjects underwent cardiopulmonary exercise test to assess peak oxygen consumption (peak VO2). Echocardiographic images were analysed off-line. Apical and basal rotation and radial displacement were measured by speckle tracking. Longitudinal displacement was assessed by colour tissue Doppler imaging. Raw data and timing of events were analysed using a custom-written interpolation algorithm. SDSM (SD of four LV peak systolic motions: basal and apical rotation, longitudinal and radial displacement) was calculated. Results SDSM was comparable at rest for all three groups but controls showed the highest reduction in SDSM compared to both groups of patients on exercise. Patients with LVH had the smallest reduction in SDSM implying greater dyssynchrony in LV motions on exercise. SDSM on exercise correlated with left ventricular mass index (r=0.362, p=0.002) and VO2max (r=−0.319, p=0.011). Conclusion LVH in patients with HFNEF is associated with intramural dyssynchrony and uncoupling of the complex 3-dimensional LV motions on exercise. This might contribute to their exertional symptoms.Abstract 008 Table 1 HFNEF with LVH HFNEF without LVH Controls p-value (ANOVA) SD systolic motions (ms) at Rest 53.3±32.7 45.5±33.2 44.8±25.7 0.456 SD systolic motions (ms) on exercise 48.0±28.3* † 28.7±18.7 25.7±15.7 <0.001* p<0.05 compared to controls.† p<0.05 compared to HFNEF patients without LVH.