Table 2.
Characteristics comparison between subjects with increase in Q or plateau/decrease in Q (n = 61)
| Increase in Q (n = 40) | Plateau/decrease in Q (n = 21) | χ2 value (df) | p-value | |
|---|---|---|---|---|
| Age (years) | 63 ± 10 | 64 ± 9 | n.a. | NS |
| Gender male/female (%) | 33 (83)/7 (17) | 18 (86)/3 (14) | 0.10 (1) | NS |
| Etiology ICM/DCM (%) | 21 (53)/19 (47) | 13 (62)/8 (38) | 0.49 (1) | NS |
| Duration CHF (months) | 45 ± 50 | 46 ± 54 | n.a. | NS |
| Beta blocker (%) | 93 | 95 | 0.17 (1) | NS |
| NYHA class II/III (%) | 24 (60)/16 (40) | 11 (52)/10 (48) | 0.33 (2) | NS |
| LVEF (%) | 31 ± 8 | 33 ± 10 | n.a. | NS |
| Peak VO2 (mL min−1 kg−1) | 19.4 ± 6.0 | 18.2 ± 5.9 | n.a. | NS |
| Peak Q (L min−1) | 11.3 ± 3.6 | 10.2 ± 5.0 | n.a. | NS |
| Peak SV (mL) | 90 ± 24 | 83 ± 22 | n.a. | NS |
| Plateau/decrease in VO2 | 9 (23 %) | 11 (52 %) | 5.58 (1) | 0.02 |
| Plateau/decrease in SV | 30 (75 %) | 21 (100 %) | 6.28 (1) | 0.01 |
| Rest HR (beats min−1) | 81 ± 16 | 77 ± 18 | n.a. | NS |
| Peak HR (beats min−1) | 126 ± 20 | 121 ± 35 | n.a. | NS |
| Chronotropic incompetence | 1 (2.5 %) | 5 (31 %) | 7.05 (1) | 0.01 |
| Rhythm (SR, Afib, paced) (%) | 35 (88)/2 (5)/3 (7) | 15 (71)/5 (24)/1 (5) | 4.85 (2) | NS |
| LBBB | 19 (48 %) | 4 (19 %) | 4.84 (1) | 0.03 |
| Severe mitral regurgitation | 3 (7.5 %) | 3 (14 %) | 0.72 (1) | NS |
| Myocardial ischemia | 2 (5 %) | 0 (0 %) | 1.09 (2) | NS |
χ2 value, chi-squared value for categorical values, df degree of freedom,n.a. not applicable, ICM ischemic cardiomyopathy, DCM dilated cardiomyopathy, CHF chronic heart failure, NYHA New York Heart Association, LVEF left ventricular ejection fraction, VO2 oxygen uptake, Q cardiac output, SV stroke volume, HR heart rate, SR sinus rhythm, Afib atrial fibrillation, LBBB left bundle branch block, . NS non significant