The evaluation of doxorubicin-induced cardiotoxicity: comparison of Doppler and tissue Doppler-derived myocardial performance index.

BACKGROUND: Doxorubicin is a chemotherapeutic agent used in a wide spectrum of cancers. However, cardiotoxic effects have limited its clinical use. The early detection of doxorubicin-induced cardiotoxicity is crucial. The purpose of our study was to assess values of Doppler and tissue Doppler imaging (TDI)-derived myocardial performance index (MPI) in adult cancer patients receiving doxorubicin treatment. METHODS: A total of 45 patients underwent echocardiographic examinations before any doxorubicin had been administered and then after doxorubicin. Doppler and TDI-derived MPI of left ventricular (LV) were determined in the evaluation of cardiotoxicity. Additionally, TDI-derived MPI of right ventricular (RV) was determined. RESULTS: All patients underwent control echocardiographic examination after mean 5 ± 1.7 months. The LV MPI obtained by both Doppler and TDI were increased after doxorubicin treatment (0.56 ± 0.11, 0.61 ± 0.10, p = 0,005 vs 0.51 ± 0.09, 0.59 ± 0.09, p = 0.001, respectively). There was no correlation between Doppler-derived MPI and cumulative doxorubicin dose (coefficient of correlation 0.11, p = 0.6). TDI-derived MPI was correlated with cumulative doxorubicin dose (coefficient of correlation 0.35, p = 0.015), but this correlation is weak (r = 0.38). The study population was divided into two groups according to doxorubicin dose (below and above 300 mg level). There was a moderate correlation between TDI-derived MPI and less than 300 mg of doxorubicin dose (coefficient of correlation 0.51, p = 0.028). However, Doppler-derived MPI was not correlated with less than 300 mg of doxorubicin dose (coefficient of correlation 0.38, p = 0.123). Also, there was no significant change in the TDI-derived RV-MPI (0.49 ± 0.14, 0.50 ± 0.12, p = 0.56). CONCLUSIONS: TDI-derived MPI is a useful parameter and an early indicator compared with Doppler-derived MPI in the detection of cardiotoxicity during the early stages. Also, doxorubicin administration does not affect RV function.

Correlation of the myocardial performance index with plasma B-type natriuretic peptide levels in type 2 diabetes mellitus and impaired glucose tolerance.

BACKGROUND AND AIM: In this study, we aimed to evaluate myocardial functions in patients with diabetes mellitus (DM) and impaired glucose tolerance (IGT). We also aimed to investigate the relationship between B-type natriuretic peptide (BNP) levels and myocardial performance index (Tei index) in these patients. METHODS: A total of 38 patients with DM, 34 patients with IGT, and 40 healthy volunteers were recruited to the study. Basal clinical and laboratory findings were recorded. BNP levels of all individuals were measured. Both conventional transthoracic and tissue Doppler echocardiogaphy were performed to all study participants. RESULTS: B-type natriuretic peptide levels of the diabetic group were greater than in patients with IGT and the control group. BNP levels of the IGT group were also higher than the control group. Myocardial performance index values, measured by both the conventional method and tissue Doppler echocardiography, were significantly higher in the diabetic group than in the control group. There was a significant relationship between myocardial performance index and BNP levels. CONCLUSIONS: Myocardial functions are disturbed in patients with DM and also in patients with IGT. BNP and myocardial performance index can be used in diabetic patients and in patients with IGT to define myocardial dysfunction.

The effect of diabetes mellitus on the P-wave dispersion.

BACKGROUND: P-wave dispersion (PD), a measure of heterogeneity of atrial refractoriness, is defined as the difference between the minimum (P min) and maximum P-wave (P max) durations on standard 12-lead electrocardiography (ECG). Increase in PD shows the intra-atrial and inter-atrial non-uniform conduction. In the present study the evaluation of the effect of diabetes mellitus (DM) on PD in patients without coronary artery disease and hypertension was carried out. METHODS AND RESULTS: Seventy-six diabetic patients who had no coronary artery disease or hypertension (group 1; mean age 48+/-9) and 40 healthy volunteer individuals (group 2; mean age 46+/-13) were enrolled in the study. After obtaining 12-lead surface ECG of all cases, P max and P min P-wave durations were measured and the differences between them were taken as PD (PD=P max-P min). Left atrium diameter, left ventricular end systolic and end diastolic diameters were measured and left ventricular ejection fraction was determined by echocardiography. Pulse wave mitral flow velocities were measured from the apical 4-chamber view. Mitral early diastolic velocity (E), late diastolic velocity (A), E/A, E deceleration time and isovolumetric relaxation time were determined. In comparison of the 2 groups there was no statistically significant difference among age, sex, systolic and diastolic blood pressure, resting heart rate and body mass index of the cases. Although PD and P max were significantly higher in diabetic patients, there was no difference between P min values (33+/-12 vs 28+/-10, p=0.02; 99+/-12 vs 93+/-10, p=0.011; 66+/-9 vs 65+/-10, p=NS; respectively). CONCLUSIONS: DM might increase PD even without ischemia, hypertension and left ventricular hypertrophy.