Yu Ting Tan

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.

Forgotten atrial: driver of symptoms in heart failure with normal ejection fraction?

Recently it has become apparent that there are a variety of abnormalities of systolic and diastolic function in patients with heart failure and a normal (or ‘preserved’) ejection fraction (HFNEF). These include reduced myocardial systolic strain, reduced ventricular systolic rotation, reduced mitral annular motion in systole and diastole, and delayed ventricular untwisting associated with reduced left ventricular (LV) suction, all of which fail to increase normally on exercise.1–3 Abnormalities of systolic function with subsequent reduced early diastolic filling lead to a greater dependence on atrial contribution towards late diastolic filling. Active atrial contraction acts as a booster to augment LV filling, particularly in compensation for shortened diastolic filling time due to increased heart rate on exercise. Similarly, such atrial compensation plays a significant role when early diastolic filling is reduced with LV hypertrophy due to hypertensive heart disease, which is one of the common precursors of HFNEF. Until recently, there has been little information on left atrial (LA) function in HFNEF. LA function has been shown to contribute significantly to stroke volume in conditions such as …

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.

81 Dyssynchronous three plane motion and impaired left ventricular twist 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. Recent publications showed a loss of apical rotation and longitudinal function particularly on exercise in these patients. Whether a deterioration of basal rotation and a dyssynchrony of different three plane motions on exercise might contribute to symptoms in these patients is not known. Method 72 Patients (age 73±7 years, 48 female) with breathlessness on exertion and normal EF (60±7%) underwent cardiopulmonary exercise test to rule out alternative clinical reasons (VO2max 18.4±4.9 ml/min/kg). Data were compared to 38 age-matched control subjects (age 71±7 years, 29 female, EF 63±7%) with a normal exercise tolerance (VO2max 28.6±5.1 ml/min/kg). All underwent full Doppler 2D-echocardiography at rest and on supine exercise. Echo images were analysed off-line. Apical and basal rotation, longitudinal and radial displacement were measured by speckle tracking. Speckle tracking pictures and colour TDI curves were loaded into custom made software. The software interpolated all curves and calculated twist as the difference of rotation at apex and at base. The software offered timing information to calculate SD and time delays for different motions. Results As previously described apical rotation was reduced at rest and on exercise Basal rotation was comparable at rest but significantly reduced on exercise in patients. The SD for four different systolic peak motions (basal and apical rotation, longitudinal and radial displacement) was comparable at rest but on exercise controls showed a significantly reduced SD compared to patients showing a greater ability to synchronise motions. Furthermore a ratio of untwist during IVRT and longitudinal extension (Ratio Untwist /Extension in IVRT) showed a significant deeper slope on exercise for patients indicating a loss of synchrony in diastole, too. All results are presented in Abstract 81 table 1.Abstract 81 Table 1 Patients Rest Controls Rest p value Patients Exercise Controls Exercise p value Apical Rotation (°) 9.9±4.4 13.4±4.0 <0.001 12.5±4.7 16.6±3.9 <0.001 Basal Rotation (°) −8.3±3.3 −8.0±3.4 0.676 −7.7±3.2 −9.7±3.0 0.011 Twist (°) 18.0±5.7 21.0±4.9 0.01 19.5±5.9 25.9±6.0 <0.001 SD Systolic Motions (ms) 48.6±32.9 43.1±25.3 0.38 40.1±27.1 25.9±15.5 0.01 Ratio Untwist/Extension in IVRT (°/mm) 25.3±51.4 7.1±10.7 0.059 9.6±14.7 3.3±3.8 0.034 Conclusion Patients with HFNEF show a deterioration of basal rotation and a systolic and diastolic three plane dyssynchrony particularly on exercise. This might further contribute to the deterioration of early diastolic suction and therefore decrease stroke volume on exercise. This might be a major contribution to their symptoms.