Kjetil Steine

Quantification of left ventricular systolic function by tissue Doppler echocardiography: added value of measuring pre- and postejection velocities in ischemic myocardium.

Background—Tissue Doppler imaging (TDI) is a potentially powerful method for diagnosing myocardial ischemia. This study was designed to investigate how velocity patterns in ischemic myocardium relates to regional function, and to determine whether timing of velocity measurements relative to ejection and isovolumic phases may increase the diagnostic power of TDI. Methods and Results—In 17 open-chest anesthetized dogs we measured pressures by micromanometers, myocardial longitudinal segment lengths by sonomicrometry, and velocities by TDI. Myocardial longitudinal strain rate was calculated as velocity divided by distance to the left ventricle apex. Moderate ischemia (left anterior descending coronary artery stenosis) caused parallel reductions in regional systolic shortening by sonomicrometry (P <0.05) and in peak systolic velocities by TDI (P <0.05). Severe ischemia (left anterior descending coronary artery occlusion), however, induced systolic lengthening by sonomicrometry (P <0.001), whereas peak TDI velocity during ejection remained positive (P <0.05). When velocities during isovolumic contraction (IVC) and isovolumic relaxation (IVR) were included, TDI correlated well with sonomicrometry; ie, systolic lengthening occurred predominantly during IVC and was evident as negative velocities (r =0.70, P <0.001), and postsystolic shortening during IVR (r =0.72, P <0.001) as positive velocities. In nonischemic myocardium peak systolic strain rates were more uniform than velocities. Conclusion—The present results indicate that peak ejection velocity is an inappropriate measure of function in severely ischemic myocardium. Dyskinetic myocardium deforms predominantly during the isovolumic phases, and therefore IVC and IVR velocities are better markers of function. When isovolumic as well as ejection velocities are measured, TDI has excellent ability to quantify regional myocardial dysfunction. Longitudinal strain rates are more uniform than velocities and may further improve the diagnostic power of TDI.

Prevention of cardiac dysfunction during adjuvant breast cancer therapy (PRADA): a 2 × 2 factorial, randomized, placebo-controlled, double-blind clinical trial of candesartan and metoprolol

Abstract Aims Contemporary adjuvant treatment for early breast cancer is associated with improved survival but at the cost of increased risk of cardiotoxicity and cardiac dysfunction. We tested the hypothesis that concomitant therapy with the angiotensin receptor blocker candesartan or the β-blocker metoprolol will alleviate the decline in left ventricular ejection fraction (LVEF) associated with adjuvant, anthracycline-containing regimens with or without trastuzumab and radiation. Methods and results In a 2 × 2 factorial, randomized, placebo-controlled, double-blind trial, we assigned 130 adult women with early breast cancer and no serious co-morbidity to the angiotensin receptor blocker candesartan cilexetil, the β-blocker metoprolol succinate, or matching placebos in parallel with adjuvant anticancer therapy. The primary outcome measure was change in LVEF by cardiac magnetic resonance imaging. A priori, a change of 5 percentage points was considered clinically important. There was no interaction between candesartan and metoprolol treatments (P = 0.530). The overall decline in LVEF was 2.6 (95% CI 1.5, 3.8) percentage points in the placebo group and 0.8 (95% CI −0.4, 1.9) in the candesartan group in the intention-to-treat analysis (P-value for between-group difference: 0.026). No effect of metoprolol on the overall decline in LVEF was observed. Conclusion In patients treated for early breast cancer with adjuvant anthracycline-containing regimens with or without trastuzumab and radiation, concomitant treatment with candesartan provides protection against early decline in global left ventricular function.

Mechanisms of Retarded Apical Filling in Acute Ischemic Left Ventricular Failure

BACKGROUND We examined the hypothesis that retardation of apical filling as measured by color M-mode Doppler echocardiography in the diseased left ventricle (LV) reflects a decrease in the intraventricular mitral-to-apical pressure gradient. METHODS AND RESULTS In 9 open-chest anesthetized dogs, micromanometers were placed near the mitral tip and in the apical region. From the color M-mode Doppler images, the time delay (TD) between peak velocity at the mitral tip and the apical region was determined as an index of LV flow propagation. Acute ischemic LV failure was induced by coronary microembolization. Induction of ischemia caused a marked increase in LV end-diastolic pressure and a decrease in LV ejection fraction. The time constant of LV isovolumic apical pressure decay (tau) increased from 31+/-8 to 49+/-16 ms (P<0.001). The peak early diastolic mitral-to-apical pressure gradient (DeltaPLVmitral-apex) decreased from 1.9+/-0.9 to 0.7+/-0.5 mm Hg (P<0.01), and TD increased from 5+/-3 to 57+/-26 ms (P<0.001). The slowing of flow propagation was limited to the apical portion of the LV cavity. The TD correlated with DeltaPLVmitral-apex (r=-0.94, P<0.01) and with tau (r=0.92, P<0.01). Before ischemia, the mitral-to-apical flow propagation velocity far exceeded the velocity of the individual blood cells, whereas during ischemia, flow propagation velocity approximated the blood velocity. CONCLUSIONS Retardation of apical filling in acute ischemic failure was attributed to a decrease in the mitral-to-apical driving pressure, reflecting slowing of LV relaxation. The slowing of flow propagation appeared to represent a shift in apical filling from a pattern of column motion to a pattern dominated by convection.

Haemodynamic responses to exercise in patients with COPD

The present study aimed to explore the prevalence of pre-capillary pulmonary hypertension (PH) and characterise haemodynamic vascular responses to physical exercise in chronic obstructive pulmonary disease (COPD) outpatients, where left ventricular dysfunction and comorbidities were excluded. 98 patients with COPD underwent right heart catheterisation at rest and during supine exercise. Mean pulmonary artery pressure (Ppa), pulmonary capillary wedge pressure (Ppcw) and cardiac output (CO) were measured at rest and during exercise. Exercise-induced increase in mean Ppa was interpreted relative to increase in blood flow, mean Ppa/CO, workload (W) and mean Ppa/W. Pulmonary vascular resistance (PVR) and pulmonary artery compliance (PAC) were calculated. PH at rest was defined as mean Ppa at rest ≥25 mmHg and Ppcw at rest <15 mmHg. Prevalence of PH was 5%, 27% and 53% in Global Initiative for Chronic Obstructive Lung Disease stages II, III and IV, respectively. The absolute exercise-induced rise in mean Ppa did not differ between subjects with and without PH. Patients without PH showed similar abnormal haemodynamic responses to exercise as the PH group, with increased PVR, reduced PAC and steeper slopes for mean Ppa/CO and mean Ppa/W. Exercise revealed abnormal physiological haemodynamic responses in the majority of the COPD patients. The future definition of PH on exercise in COPD should rely on the slope of mean Ppa related to cardiac output and workload rather than the absolute values of mean Ppa.

Rationale and Design of the Prevention of Cardiac Dysfunction during an Adjuvant Breast Cancer Therapy (PRADA) Trial

Objective: The PRevention of cArdiac Dysfunction during Adjuvant breast cancer therapy (PRADA) study is a randomized, placebo-controlled, double-blind trial to determine whether angiotensin receptor blockers (ARB), or beta-blockers or their combination may prevent the development of left ventricular (LV) dysfunction in patients on standard adjuvant treatment for early breast cancer. Methods: Following surgical resection, 120 breast cancer patients scheduled for adjuvant epirubicin-containing chemotherapy and, if indicated, trastuzumab, will be included. They will be randomized to an ARB (candesartan), a beta-blocker (metoprolol) and matching placebos in a 2 × 2 factorial design. The primary objective of the PRADA study is to assess whether prophylactic ARB and/or beta-blockers may prevent a reduction in LV ejection fraction (EF) after adjuvant treatment of early breast cancer, as evaluated by serial cardiovascular magnetic resonance (CMR) performed at randomization, after the first chemotherapy cycle and on its completion, and for subgroups, on completion of radiotherapy or trastuzumab. Secondary outcome measures include echocardiographic indices of LV diastolic dysfunction, structural myocardial alterations assessed by CMR and changes in cardiac biomarkers. Conclusion: PRADA may provide new information on the prophylactic effect of ARB and beta-blockers in patients with early breast cancer regarding the risk of developing cardiac dysfunction from adjuvant cancer treatment.

Left Ventricular Systolic and Diastolic Function in Asymptomatic Patients With Moderate Aortic Stenosis

Tissue Doppler imaging (TDI) has improved the ability to detect subclinical changes in left ventricular (LV) function. The aim of this study was to investigate if asymptomatic patients with moderate aortic stenosis (AS) had impaired LV systolic and diastolic function. Fifty patients (mean age 65 +/- 12 years) recruited into the multicenter Simvastatin + Ezetimibe in Aortic Stenosis (SEAS) study with aortic peak velocities of 2.5 and 4.0 m/s were compared with 26 healthy subjects (mean age 64 +/- 12 years) (p = NS). Peak systolic tissue velocities and strain were measured at 8 LV locations and averaged. Early diastolic tissue velocity from the septal mitral annulus (Esep) was measured as an index of LV relaxation. The ratio of early diastolic transmitral pulsed Doppler (E) to Esep (E/Esep) was calculated as an index of LV filling pressure. Peak systolic tissue velocity (4.1 +/- 1.0 vs 4.8 +/- 1.1 cm/s, p <0.01) and strain (-16.6 +/- 2.7% vs -17.9 +/- 2.0%, p <0.05) were decreased in patients with AS compared with controls. Esep was decreased (4.9 +/- 1.0 vs 5.8 +/- 1.3 cm/s, p <0.01) and E/Esep was increased (17.4 +/- 9.7 vs 11.7 +/- 3.8, p <0.01) in the AS group compared with the control group. In conclusion, asymptomatic patients with moderate AS have impaired LV systolic function as measured by reduced peak systolic tissue velocity and strain. Augmented LV filling pressure measured by E/Esep and impaired LV relaxation measured by reduced Esep also indicate diastolic dysfunction in these patients.

Mechanics of intraventricular filling: study of LV early diastolic pressure gradients and flow velocities.

This study investigates mechanisms of left ventricular (LV) intracavitary flow during early, rapid filling. In eight coronary artery disease patients with normal LV ejection fraction we recorded simultaneous LV apical and outflow tract pressures and intraventricular flow velocities by color M-mode Doppler echocardiography. In five anesthetized dogs we also recorded left atrial pressure and LV volume by sonomicrometry. In patients, as the early diastolic mitral-to-apical filling wave arrived at the apex, we observed an apex-outflow tract pressure gradient of 3.5 ± 0.3 mmHg (mean ± SE). This pressure gradient correlated with peak early apex-to-outflow tract flow velocity ( r = 0.75, P < 0.05). The gradient was reproduced in the dog model and decreased from 3.1 ± 0.3 to 1.7 ± 0.5 mmHg ( P < 0.05) with caval constriction and increased to 4.2 ± 0.5 mmHg ( P < 0.001) with volume loading. The pressure gradient correlated with peak early transmitral flow (expressed as time derivative of LV volume; r = 0.95) and stroke volume ( r = 0.97). In conclusion, arrival of the early LV filling wave at the apex was associated with a substantial pressure gradient between apex and outflow tract. The pressure gradient was sensitive to changes in preload and correlated strongly with peak early transmitral flow. The significance of this gradient for intraventricular flow propagation in the normal and the diseased heart remains to be determined.

Cardiovascular abnormalities in adults with osteogenesis imperfecta.

BACKGROUND The aim of this study was to investigate cardiac abnormalities in adults with osteogenesis imperfecta (OI). METHODS The clinical and echocardiographic survey included 99 adults with OI divided into 3 clinical types-I, III, and IV-and 52 controls. Left ventricular end-diastolic dimensions (LVIDds), mass, and 4 aortic diameters were measured by standard echocardiography and indexed for body surface area. RESULTS Hypertension was registered in 37 individuals (37.4%). The OI group had significantly lower body surface area than the control individuals, 1.7 ± 0.3 versus 1.9 ± 0.2 m(2) (P < .05). The LVIDd and LV mass were significantly larger in the OI group when compared with the controls, 2.98 ± .64 versus 2.59 ± .26 cm/m(2) (P < .05) and 97.3 ± 30.1 versus 73.3 ± 18.0 g/m(2) (P < .05), respectively. Type III OI showed significantly enlarged LVIDd as compared with types I and IV OI, 4.33 ± 1.10 versus 2.83 ± .33 (P < .05) versus 2.85 ± .37 cm/m(2) (P < .05), respectively. All aortic diameters were significantly larger in the OI group than in the control group, as they were in type III compared with types I and IV; 10.1% mild aortic regurgitation (AR), 10.1% moderate AR, and 7.1% moderate mitral regurgitation were registered in the OI group. CONCLUSIONS Increased LVIDd, LV mass, mitral regurgitation, and AR were found in adult patients with OI compared with the control group. The changes in LV and dilatation of aorta seemed to be more pronounced in patients with type III compared with types I and IV OI.

Mechanisms of Diastolic Intraventricular Regional Pressure Differences and Flow in the Inflow and Outflow Tracts

OBJECTIVES We sought to investigate the mechanisms of left ventricular (LV) intracavitary early diastolic flow during changes in contractility and loading. BACKGROUND There is limited understanding of how intracavitary flow velocities relate to intraventricular driving pressures. METHODS In 12 anesthetized dogs, we measured pressures in the left atrium (LA), LV at the mitral tip, apex, and subaortic region; intraventricular velocities by color M-mode Doppler echocardiography (CMD); and volume by sonomicrometry. We also investigated responses to isoprenaline, ischemic failure, and volume loading. RESULTS During rapid, early filling, the mitral to apical pressure gradient (LVP(mitral-apex)) correlated with the peak mitral to apical velocity (r = 0.92). The LVP(mitral-apex) increased from 1.4 +/- 0.6 (SD) to 3.2 +/- 1.8 mm Hg during isoprenaline (p < 0.05) and decreased to 0.6 +/- 0.5 during ischemic failure (p < 0.01). The pressure gradient correlated positively with the time constant of isovolumic relaxation (tau) (r = 0.82) and negatively with LV end-systolic volume (ESV) (r = -0.77). Volume loading increased LA pressure, tau, and ESV, but caused no significant change in LVP(mitral-apex). At baseline and during isoprenaline, tau was shorter (p < 0.05) at the apex than at the base. When the mitral to apical gradient approached zero, filling velocities were directed toward the LV outflow tract, and a pressure gradient was established between the apex and subaortic region. CONCLUSIONS Changes in LVP(mitral-apex) induced by inotropic stimuli, loading, and ischemia appeared to reflect dependency of the pressure gradient on the rate of relaxation, ESV, and LA pressure. Regional differences in the rate of relaxation may also contribute to intraventricular pressure gradients. These findings have implications for how to interpret intraventricular filling in a clinical context.

Early Diastolic Intraventricular Filling Pattern in Acute Myocardial Infarction by Color M-mode Doppler Echocardiography

The aim of the present study was to investigate whether slowing of mitral-to-apical filling is present in patients with acute myocardial infarction (AMI). Twenty-eight patients with their first AMI were examined by color M-mode Doppler echocardiography. Twenty-eight age- and sex-matched healthy individuals served as control subjects. From the color M-mode Doppler images, we measured the time difference (TD) between occurrence of peak flow velocity at the mitral tip and in the apical region by a blinded analysis. The TD was increased in the AMI group compared with the control subjects (70 +/- 60 versus 40 +/- 30 msec, p = 0.02) and correlated with peak SGOT (r = 0.46, p = 0.02) and age (r = 0.57, p < 0.01). In the 15 patients with anterior AMI, the correlation between TD and SGOT was better (r = 0.68, p < 0.01). This study demonstrated slowing of early diastolic mitral-to-apical flow propagation in patients with AMI. Infarction size and age appear to be of importance for the retardation of mitral-to-apical flow propagation.