Table 3.
Echocardiographic parameters
| Clozapine (n=100) | Non-clozapine (n=21) | Controls (n=20) | p Value (ANCOVA) | |
|---|---|---|---|---|
| Cardiac chamber dimensions | ||||
| RVEDA (cm2) | 9.8±2.6 | 11.7±2.7 | 10.9±3.5 | 0.09 |
| LVEDA (cm2) | 25.5±5.3 | 29.8±5.1 | 27.1±5.6 | 0.002* |
| RVEDA : LVEDA ratio | 0.39±0.08 | 0.37±0.07 | 0.40±0.09 | 0.48 |
| RA area (cm2) | 12.1±2.5 | 11.4±3.3 | 12.4±2.7 | 0.08 |
| LA area (cm2) | 15.0±3.2 | 16.0±4.0 | 14.5±2.9 | 0.93 |
| RA : LA area ratio | 0.83±0.2 | 0.72±0.14 | 0.87±0.2 | 0.04 |
| LVEDV (mL) | 96.5±27.9 | 106.5±30.1 | 109.5±26.3 | 0.49 |
| LVESV (mL) | 38.9±14.7 | 39.2±15.1 | 38.1±12.4 | 0.75 |
| RV function | ||||
| RVFAC (%) | 47.5±10.3 | 43.9±6.7 | 48.5±8.9 | 0.49 |
| TAPSE (cm) | 2.3±0.3 | 2.2±0.2 | 2.4±0.2 | 0.10 |
| PASP (mm Hg) | 22.7±6.5 | 23.0±3.6 | 24.3±4.7 | 0.94 |
| LV systolic function | ||||
| Conventional parameters | ||||
| Fractional shortening (%) | 32.1±4.8 | 35.9±4.0 | 36.4±5.7 | 0.001†* |
| M-mode EF (%) | 60.7±6.1 | 65.7±4.7 | 65.6±6.9 | 0.003†* |
| Simpson's EF (%) | 58.3±5.3 | 62.2±5.3 | 64.8±5.8 | <0.001†* |
| Simpson's EF <55% | 27 | 0 | 0 | 0.006 |
| Simpson's EF <50% | 9 | 0 | 0 | 0.19 |
| LV-modified Tei index | 0.59±0.13 | 0.59±0.08 | 0.50±0.15 | 0.04 |
| Novel parameters | ||||
| 2D speckle systolic strain (%) | ||||
| Global longitudinal strain | −16.7±2.1 | −18.6±1.6 | −20.2±2.3 | <0.001†‡* |
| APLAX | −16.7±2.3 | −18.1±1.6 | −20.1±3.0 | <0.001†‡* |
| 4CH | −16.6±2.4 | −19.1±2.3 | −20.0±2.4 | 0.009†* |
| 2CH | −16.9±2.5 | −19.1±2.3 | −20.7±2.6 | <0.001†* |
| LV diastolic function | ||||
| Conventional parameters | ||||
| E/E’ | 7.6±3.0 | 8.3±2.1 | 7.0±2.5 | 0.24 |
| E’ (cm/s) | 10.9±3.9 | 8.8±2.4 | 11.8±3.9 | 0.002‡* |
| A’ (cm/s) | 10.2±4.2 | 10.3±3.3 | 8.6±2.9 | 0.04‡† |
| S’ (cm/s) | 9.8±2.8 | 8.2±1.6 | 9.5±2.6 | 0.25 |
| Novel parameters: strain rate (1/s) | ||||
| 2D speckle early diastolic (E) | ||||
| Posterior wall | 1.6±0.8 | 1.8±0.3 | 1.8±0.2 | 0.39 |
| Anteroseptal wall | 1.5±0.5 | 1.7±0.5 | 1.8±0.9 | 0.12 |
| Inferoseptal wall | 1.4±0.5 | 1.6±0.4 | 1.6±0.3 | 0.49 |
| Lateral wall | 1.5±0.5 | 1.8±0.4 | 1.8±0.2 | 0.15 |
| Inferior wall | 1.5±0.4 | 1.6±0.5 | 1.6±0.3 | 0.41 |
| Anterior wall | 1.4±0.4 | 1.6±0.4 | 1.7±0.3 | 0.07 |
Values are presented as mean±SD or absolute number (%).
ANCOVA with the following covariates in the modelling: age, alcohol excess, BMI, diabetes, family history of mental illness, gender, heart rate, history of CCF, hypercholesterolaemia, hypertension and smoking.
*Post hoc Tukey analysis with Bonferroni correction between patients receiving clozapine and non-clozapine patients, p value <0.05.
†Post hoc Tukey analysis with Bonferroni correction between clozapine and healthy controls, p value <0.05.
‡Post hoc Tukey analysis with Bonferroni correction between non-clozapine and healthy controls, p value <0.05.
2CH, 2 chamber view; 2D, two-dimensional; A’, late diastolic/atrial contraction myocardial tissue Doppler velocity measured at lateral mitral annulus; ANCOVA, analysis of covariance; APLAX, apical long axis view; BMI, body mass index; CCF, congestive cardiac failure; E’, early diastolic myocardial tissue Doppler velocity measured at lateral mitral annulus; E/E’, ratio of mitral peak velocity of early filling (E) to early diastolic mitral annual velocity (E’); EF, ejection fraction; LA, left atrium; LV, left ventricle; LVEDA, left ventricular end diastolic area; LVEDV, left ventricular end diastolic volume; LVESV, left ventricular end systolic volume; PASP, pulmonary artery systolic pressure; RA, right atrium, RV, right ventricle; RVEDA, right ventricular end diastolic area; RVFAC, right ventricular fractional area change; S’, peak systolic myocardial tissue Doppler velocity measured at lateral annulus; TAPSE, tricuspid annular plane systolic excursion.