Theodora Zaglavara

Evidence of Left Ventricular Dysfunction in Asymptomatic Elderly Patients with Non-insulin-dependent Diabetes Mellitus

Diabetic cardiomyopathy is a distinct entity in diabetic patients with congestive heart failure, who have no angiographic evidence of significant coronary artery stenosis. The aim of this study was to evaluate left ventricular (LV) function in 24 elderly patients (mean age 67 ±2 years) with type 2 diabetes, who were asymptomatic and had no history of hypertension, or coronary or valvular heart disease. LV systolic indices (ejection fraction [EF] and fractional shortening [FS]), diastolic indices (E wave, A wave, E/A ratio, isovolumic relaxation time [IVRT] and deceleration time [DT]) and the myocardial performance index (MPI) were evaluated with echocardiography. Compared to controls (24 age- and gender-matched normal subjects), the E wave was reduced (0.60 ±0.10 m/sec vs 0.72 ±0.08 m/sec, p<0.05), the A wave was increased (0.77 ±0.07 m/sec vs 0.68 ±0.06 m/sec, p<0.05), the E/A ratio was decreased (0.78 ±0.20 vs 1.06 ±0.18, p<0.001) and both IVRT and DT were prolonged (0.115 ±0.01 sec vs 0.09 ±0.01 sec, p<0.001 and 0.240 ±0.04 sec vs 0.180 ±0.03 sec, p<0.001, respectively). The MPI was significantly increased (0.640 ±0.170 vs 0.368 ±0.098, p<0.001). LV diastolic function and the MPI are markedly impaired in asymptomatic elderly patients with type 2 diabetes.

Dobutamine stress echocardiography for the detection of myocardial viability in patients with left ventricular dysfunction taking β blockers: accuracy and optimal dose

Objective: To assess the accuracy of dobutamine stress echocardiography (DSE) and the optimal dose of dobutamine to detect myocardial viability in patients with ischaemic left ventricular (LV) dysfunction who are taking β blockers, using the recovery of function six months artery revascularisation as the benchmark. Patients: 17 patients with ischaemic LV dysfunction (ejection fraction < 40%) and chronic treatment with β blockers scheduled to undergo surgical revascularisation. Setting: Regional cardiothoracic centre. Methods: All patients underwent DSE one week before and resting echocardiography six months after revascularisation. A wall motion score was assigned to each segment for each dobutamine infusion stage, using the standard 16 segment model of the left ventricle. The accuracy of DSE to predict recovery of resting segmental function was calculated for low dose (5 and 10 μg/kg/min) and for a full protocol of dobutamine infusion (5 to 40 μg/kg/min). Results: Of the 272 segments studied, 158 (58%) were dysfunctional at rest, of which 79 (50%) improved at DSE and 74 (47%) recovered resting function after revascularisation. Analysis of results with a low dose showed a significantly lower sensitivity and negative predictive value than with a full protocol (47% v 81%, p < 0.001 and 65% v 82%, p < 0.05, respectively). The accuracy in the full protocol analysis was comparable with that reported in patients no longer taking β blockers but was significantly lower than that in the low dose analysis (78% v 66%, p < 0.001). Conclusions: Findings suggest that β blocker withdrawal is not necessary before DSE when viability is the clinical information in question. However, a completed protocol with continuous image recording is required to detect the full extent of viability.

Detection of myocardial viability by dobutamine stress echocardiography: incremental value of diastolic wall thickness measurement

Objective: To assess the diagnostic accuracy of baseline diastolic wall thickness (DWT) alone and as an adjunct to dobutamine stress echocardiography (DSE) for prediction of myocardial viability in patients with ischaemic left ventricular (LV) dysfunction, with the recovery of resting function after revascularisation as the yardstick. Patients: 24 patients with ischaemic LV dysfunction (ejection fraction < 40%) scheduled for surgical revascularisation. Setting: Regional cardiothoracic centre. Methods: All patients underwent DSE before and resting echocardiography six months after revascularisation. DWT was measured in each of the 16 LV segments. A receiver operating characteristic (ROC) and a multi-ROC curve were generated to assess the ability of DWT alone and in combination with DSE to predict myocardial viability. Results: DWT > 0.6 cm provided a sensitivity of 80%, a specificity of 51%, and a negative predictive value of 80% for the prediction of viability in akinetic segments. DSE had an excellent specificity (92%) but a modest sensitivity (60%) in akinetic segments. A combination of improvement at DSE or DWT > 0.8 cm improved sensitivity (90% v 60%, p < 0.001) and negative predictive value (92% v 78%, p  =  0.03) in akinetic segments compared with DSE alone. This was achieved with some loss in specificity (75% v 92%, p  =  0.01) and positive predictive value (71% v 82%, p  =  0.79). Conclusions: DWT measurement may improve the sensitivity of DSE for the detection of myocardial viability. Akinetic segments with DWT > 0.8 cm have a good chance of recovery despite the absence of contractile reserve during DSE. Further testing may be required before excluding myocardial viability in these cases.

Evaluation of a Doppler-Derived Index Combining Systolic and Diastolic Left Ventricular Function in Acute Myocardial Infarction

Assessment of left ventricular (LV) function is crucial in the immediate postinfarction period. The authors evaluated the clinical applicability of the Doppler-derived myocardial performance index (MPI, defined as the sum of isovolumic contraction and relaxation times divided by LV ejection time) in patients with acute myocardial infarction (AMI) as to whether this index reflects the severity of LV dysfunction in this subgroup of patients. Post-AMI patients (n = 33) were compared with age- and sex-matched healthy subjects (n = 35). Within 24 hours of the AMI and 1 month thereafter, patients underwent 2D and Doppler echocardiography. Patients were divided into group A (Killip Class I, n = 22) and group B (Killip Class II-III, n = 11). The authors measured the LV ejection fraction (EF), diastolic indices (transmitral E and A waves, E/A ratio, deceleration time [DT], isovolumic contraction time [IVCT], isovolumic relaxation time [IVRT], MPI, LV end-systolic and end-diastolic volume indices [ESVi and EDVi] and wall motion score index [WMSi]). One-year mortality was also assessed. There was no significant difference concerning E and A waves, E/A ratio, and IVRT between the 2 groups. There were highly statistical differences at day 1 for EF (59.3 ± 6.7% vs 36.8 ± 4.5%, p<0.0001), DT (0.160 ± 0.030 sec vs 0.127 ± 0.022, p < 0.005), MPI (0.344 ± 0.084 vs 0.686 ± 0.120, p < 0.0001), ESVi (28.4 ± 3.9 mL/m2 vs 46.2 ± 8.4, p < 0.001), and WMSi (1.58 ± 0.06 vs 1.88 ± 0.35, p = 0.05), which persisted after 1 month. One-year mortality was significantly (0 vs 27.3%, p<0.01) lower in group A patients. This study shows that the MPI, reliably indicated LV dysfunction post-AMI, significantly correlated with clinically determined functional class, and possibly has some prog nostic implication.