| 1. |
- Henein, Michael, et al.
(författare)
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Impaired left ventricular systolic function reserve limits cardiac output and exercise capacity in HFpEF patients due to systemic hypertension
- 2013
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Ingår i: International Journal of Cardiology. - : Elsevier. - 0167-5273 .- 1874-1754. ; 168:2, s. 1088-1093
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Heart failure (HF) patients with preserved left ventricular (LV) ejection fraction (EF) (HFpEF) due to systemic hypertension (SHT) are known to have limited exercise tolerance. Despite having normal EF at rest, we hypothesize that these patients have abnormal systolic function reserve limiting their exercise capacity. METHODS: Seventeen patients with SHT (mean age 68±9years) but no valve disease and 14 healthy individuals (mean age of 65±10years) underwent resting and peak exercise echocardiography using conventional, tissue Doppler and speckle tracking techniques. The differences between resting and peak exercise values were also analyzed (Δ). Exercise capacity was determined as the workload divided by body surface area. RESULTS: Resting values for left atrial (LA) volume/BSA (r=-0.66, p<0.001) and global longitudinal strain rate (GLSR) in early (e) and late (a) diastole (r=0.47 and 0.46, p<0.05 for both) correlated with exercise capacity. LVEF increased during exercise in normals (mean Δ EF=10±8%) but failed to do so in patients (mean Δ EF=0.6±9%, p<0.001 between groups). LV GLSR during systole (s) also failed to increase with exercise in patients, to the same extent as it did in normals (0.2±0.2 vs. 0.6±0.3 1/s, p<0.001). The difference between rest and exercise (Δ) in LV lateral wall systolic velocity from tissue Doppler (s') (0.71, p<0.001), Δ in cardiac output (r=0.60, p<0.001) and Δ GLSRs (r=0.48, p<0.05) all correlated with exercise capacity independent of changes in heart rate. CONCLUSION: HFpEF patients with hypertensive LV disease have significantly limited exercise capacity which is related to left atrial enlargement as well as compromised LV systolic function at the time of the symptoms. The limited myocardial systolic function reserve seems to be underlying important explanation for their limited exercise capacity.
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| 2. |
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| 3. |
- Henein, Michael, et al.
(författare)
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Long mitral valve leaflets determine left ventricular outflow tract obstruction during exercise in hypertrophic cardiomyopathy
- 2016
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Ingår i: International Journal of Cardiology. - : Elsevier. - 0167-5273 .- 1874-1754. ; 212, s. 47-53
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Development of left ventricular outflow tract obstruction (LVOTO) in patients with hypertrophic cardiomyopathy (HCM) is important for explaining symptoms and designing management. LVOTO is mostly caused by a combination of septal hypertrophy and systolic anterior movement of the mitral valve (SAM). The aim of the present study was to determine predictors of exercise induced LVOTO in a group of HCM patients.METHODS: We performed supine exercise Doppler echocardiography, including measurements of LV morphology and function and anterior mitral leaflet length, in 51 mildly symptomatic HCM (septal thickness≥15mm) and compared them with 50 healthy controls. Measurements were made at 1) rest, 2) Valsalva maneuver, 3) peak exercise and 4) post exercise. LVOTO was diagnosed as a LVOT gradient of >30mmHg at rest, after Valsalva and after exercise or ≥50mmHg at peak exercise.RESULTS: All patients stopped exercise because of exhaustion. 35% of the patients had resting LVOTO and 48% during Valsalva. At peak exercise, only 37% had LVOTO, who increased to 64% post exercise. Patients who developed LVOTO at peak exercise were more prone to continue having it post exercise (p<0.001), to have attenuated systolic blood pressure rise (p=0.011) and to have long anterior mitral valve leaflets (p<0.001). Backward multiple regression analysis showed the anterior mitral leaflet length as the strongest single independent predictor (β=0.36, p=0.010) for increased LVOT velocities, followed by basal septal thickness.CONCLUSION: In patients with HCM, LV outflow tract obstruction seems to be relatively uncommon during exercise but rather occurring minutes after stopping exercise. Exercise LVOTO seems to be determined by long anterior mitral leaflets in addition to the well established septal hypertrophy.
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| 4. |
- Johansson, Bengt, et al.
(författare)
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Myocardial capillary supply is limited in hypertrophic cardiomyopathy : a morphological analysis
- 2008
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Ingår i: International Journal of Cardiology. - : Elsevier BV. - 0167-5273 .- 1874-1754. ; 126:2, s. 252-257
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To clarify the morphological basis of the limited coronary reserve in hypertrophic cardiomyopathy (HCM). BACKGROUND: Some of the symptoms in Hypertrophic cardiomyopathy (HCM), such as chest pain, dyspnea and arrhythmia, may be explained by myocardial ischemia. Many patients with HCM are known to exhibit these symptoms in the absence of atherosclerosis in the major coronary vessels. Decreased myocardial perfusion has been demonstrated in HCM, however, little is known about the myocardial capillary morphology in this disease. METHODS: Using immunohistochemistry and morphometry, we analysed capillaries and cardiomyocytes in myectomy specimens from 5 patients with HCM with moderate hypertrophy and left ventricular outflow tract obstruction and in 5 control hearts. RESULTS: The number of capillaries per cardiomyocyte (p<0.009) and number of capillaries per cardiomyocyte area unit, reflecting cardiomyocyte mass (p=0.009), were lower in individuals with HCM, i.e. indicating loss of capillaries. In HCM, the capillary density was 33% lower (p<0.05). CONCLUSIONS: Our morphologic findings show that the capillary supply, and thus the coronary reserve, is impaired in HCM with moderate hypertrophy and left ventricular outflow tract obstruction. These data may partly explain the limitation of myocardial perfusion in HCM, which is associated with worse prognosis. Furthermore, we present evidence of actual loss of myocardial capillaries in HCM and a defective capillary growth.
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| 6. |
- Lindqvist, Per, et al.
(författare)
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Asynchronous normal regional left ventricular function assessed by speckle tracking echocardiography : appearances can be deceptive
- 2009
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Ingår i: International Journal of Cardiology. - : Elsevier. - 0167-5273 .- 1874-1754. ; 134:2, s. 195-200
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Speckle tracking echocardiography (STE) is an angle independent method with high temporal resolution, which offers quantification of regional left ventricular (LV) wall motion. We studied radial and longitudinal LV wall motion by STE in healthy subjects with normal wall motion analysis (WMA) by eye-balling. MATERIALS AND METHODS: Eighteen healthy subjects were studied. We acquired parasternal short and apical long axis projections to determine the basal, mid and apical radial and longitudinal functions. At each level we measured; (I) radial and longitudinal peak displacement and displacement at aortic valve closure (AVC) and (II) the time interval from the Q-wave to the AVC and peak displacement. RESULTS: WMA indicated normal wall motion in all subjects. The mean peak radial displacement varied in different segments (range 3.9-9.8 mm) with highest values in the mid-level (6.9+/-1.5 mm), compared to basal level (5.9+/-1.0 mm, p<0.01) and apical level (5.4+/-1.0 mm, p<0.001). The time from Q-wave to AVC was 393 ms and in 89% of the analysed segments peak radial displacement occurred after AVC, thus mean peak radial displacement occurred 60 ms after AVC. The peak longitudinal amplitude was more synchronous with respect to AVC and with the highest amplitudes found in the two basal segments. CONCLUSIONS: In normal LV function, significant differences in peak displacement exist between segments at various LV levels using STE. In addition, in early diastole, significant discrepancy occurs between radial and longitudinal time of peak displacement, suggesting a shape change. Finally, while radial displacement was highest at mid-cavity level longitudinal displacement was highest at basal level.
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| 7. |
- Lindqvist, Per, et al.
(författare)
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Ventricular dysfunction in type 1 myotonic dystrophy : Electrical, mechanical, or both?
- 2010
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Ingår i: International Journal of Cardiology. - : Elsevier BV. - 0167-5273 .- 1874-1754. ; 143:3, s. 378-384
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Myotonic dystrophy type 1 (DM1) is a systemic disease which affects the heart and may be a cause of sudden death. Conduction disturbances are the major cardiac abnormalities seen in this condition. We sought to assess electrical and mechanical cardiac functions to identify abnormalities that might explain sudden cardiac death in DM1. METHODS: Thirty six patients with DM1 and 16 controls were studied using echocardiography including myocardial Doppler. ECG recordings were also obtained. RESULTS: Left ventricular (LV) dimensions were maintained but systolic function was reduced (p<0.001), including stroke volume (p<0.05). LV segmental myocardial isovolumic contraction time was prolonged (p<0.001) and correlated with PR interval (p<0.001). Isovolumic relaxation time was prolonged (p<0.05) and filling time was reduced (p<0.001). LV cavity was significantly asynchronous demonstrated by prolonged total isovolumic time (t-IVT) (p<0.001), high Tei index (p<0.001) and low ejection index (p<0.001). Right ventricular (RV) strain was reduced (p<0.001) as were its systolic and diastolic velocities (p<0.05 for both). 22/36 patients had prolonged LV t-IVT>12.3 s/min (upper 95% normal CI), 13 of whom had PR>/=200 ms, 11 had QRS duration >120 ms (5 had combined abnormality) and the remaining 5 had neither. Over the 3 years follow up 10 patients had events, 6 of them cardiac. t-IVT was prolonged in 5/6 patients, PR interval in 4 and QRS duration in one. CONCLUSIONS: In DM1 patients, LV conventional measurements are modestly impaired but cardiac time relations suggest marked asynchronous cavity function. Although our findings were primarily explained on the basis of long PR interval or broad QRS duration a minority presented an evidence for myocardial cause of asynchrony rather than electrical. Early identification of such abnormalities may guide towards a need for additional electrical resynchronization therapy which may improve survival in a way similar to what has been shown in heart failure trials.
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| 8. |
- Maras, Dejan, et al.
(författare)
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Patterns of cardiac dysfunction coinciding with exertional breathlessness in hypertrophic cardiomyopathy
- 2013
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Ingår i: International Journal of Cardiology. - : Elsevier. - 0167-5273 .- 1874-1754. ; 170:2, s. 233-238
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The commonest cause of breathlessness in hypertrophic cardiomyopathy (HCM) is left ventricular outflow tract (LVOT) obstruction which improves with its removal. However, in the absence of outflow tract obstruction, as in dilated cardiomyopathy, patients may be limited by similar symptoms, thus suggesting a potential common mechanism for the two conditions. We aimed to assess cardiac function at the time of symptoms in a group of unselected patients with HCM to identify other patterns of cardiac dysfunction which coincide with their breathlessness.METHODS: We studied 37 HCM patients (aged 55±15years, 13 female) with septal thickness >15mm and 17 controls (aged 58±12years, 12 female) using Doppler echocardiography, at rest and at peak dobutamine stress. Stress end points were symptoms, >20mmHg drop in systolic blood pressure, arrhythmia, or maximum dobutamine dosage of 40μg/kg/min.RESULTS: At rest: LV systolic function was maintained (EF 68±7 v 76±12%, respectively), LVOT velocity raised (p<0.005), lateral and septal long axis amplitude reduced (p<0.05 and p<0.005, respectively) and dyssynchronous and QRS duration was also broader (p<0.005) in patients compared to controls. At peak stress: Overall LVOT velocities were higher in patients than controls (4.3±1.7 v 1.7±1.0m/s, p<0.005, respectively) due to systolic anterior movement of the mitral valve and mitral regurgitation developing. In the 15 patients who did not develop significant LVOT obstruction (velocity <4m/s), LV ejection time increased and peak systolic amplitude did not increase. In the 10 patients with neither LVOT obstruction nor restrictive filling, QRS duration prolonged by 12ms (p <0.05), post-ejection shortening worsened and peak systolic amplitude fell (p<0.005). Also, LV ejection time prolonged by 5s/min (p<0.05), filling time failed to increase as it did in controls (p<0.005) and Tei index was higher than controls (p<0.01).CONCLUSION: Exertional breathlessness in HCM is associated with LV outflow tract obstruction and functional mitral regurgitation in almost two thirds of patients. The remaining one third have either resistant restrictive physiology or dyssynchronous cavity at fast heart rate. Despite similar exercise limiting breathlessness in the three groups, means of management should be quite different.
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| 9. |
- Mörner, Stellan, et al.
(författare)
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Arrhythmogenic left ventricular apical aneurysm in hypertrophic cardiomyopathy
- 2010
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Ingår i: International Journal of Cardiology. - Amsterdam : Elsevier/North Holland. - 0167-5273 .- 1874-1754. ; 151:1, s. e8-e9
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Tidskriftsartikel (refereegranskat)abstract
- A 70-year old lady with prior myectomy for hypertrophic obstructive cardiomyopathy presented with sustained ventricular tachycardia. She was found to have a large left ventricular (LV) apical aneurysm. Surgical intervention was not advised, due to the risk of creating a small LV cavity after surgery and ICD was not advised based on the risk of injuring a very thin walled aneurysm. The patient's arrhythmia settled on medical therapy, but unfortunately she suffered an unwitnessed death three months later. This case represents a rare complication to a rare disease with limited management options. In such patients evidence based medicine is of little help, if any.
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