Cardiology Research and Practice

Clinical Study

Response to Cardiac Resynchronization Therapy: The Muscular Metabolic Pathway

Table 1

Population characteristics before and after CRT.
Baseline6-month followup š‘ƒ
Subjects50
Male38 (76%)
Female12 (24%)
Age, yrs 5 9 Ā± 1 2
Left ventricular ejection fraction, % 2 4 Ā± 8 2 9 Ā± 7 <.01
Etiology
Ischaemic23 (46%)
Nonischaemic27 (54%)
SBP at rest, mmHg 1 0 8 Ā± 1 8 1 0 7 Ā± 1 7 >.05
SBP at peak, mmHg 1 3 1 Ā± 2 2 1 3 5 Ā± 2 8 >.05
HR at rest, bpm 8 1 Ā± 1 8 7 3 Ā± 1 1 <.05
HR at peak, bpm 1 1 6 Ā± 2 3 1 1 4 Ā± 2 7 >.05
Peak of VO2, ml/kg/min 1 3 Ā± 4 1 6 Ā± 5 <.05
VE/VCO2 slope 4 5 Ā± 1 6 3 9 Ā± 1 3 <.05
AT (seconds) 1 5 3 Ā± 8 2 2 4 5 Ā± 1 4 0 .01
AT VO2 1 0 Ā± 2 1 2 Ā± 4 <.05
Peak CP, mmHg ā‹… ml/kg/min 1 8 0 5 Ā± 7 4 4 2 2 2 5 Ā± 1 0 7 1 <.01
Maximal work load, Watts 7 8 Ā± 2 8 8 6 Ā± 2 6 <.05
Peak RER 1 , 1 6 Ā± 0 , 1 4 1 , 1 1 Ā± 0 , 0 7 <.05
Peak respiratory rate, /min 3 0 Ā± 8 2 7 Ā± 6 .01
Exercise duration, seconds 4 0 6 Ā± 1 7 5 4 4 9 Ā± 1 6 4 .01
NYHA class 2 , 9 8 Ā± 0 , 3 5 1 , 8 8 Ā± 0 , 4 <.01
Left ventricular end-systolic volume, ml 1 5 7 Ā± 6 9 1 2 2 Ā± 5 5 <.01
Left ventricular end-diastolic volume, ml 2 0 5 Ā± 7 9 1 7 5 Ā± 7 1 <.01
Mitral regurgitation, grade 1 . 4 9 Ā± 1 1 . 1 2 Ā± 0 . 9 <.05
QRS duration, ms 1 5 4 Ā± 3 5
Beta-blocker, %95
Diuretic, %83
Angiotensin-converting enzym inhibitor, %85
AT: anaerobic threshold, CP: circulatory power, HR: heart rate, Ms: milliseconds, NYHA: New York Heart Association, RER: respiratory exchange ratio, SBP: Systolic blood pressure, VCO2: carbon dioxide production, VE: minute ventilation, VO2: oxygen consumption, and yrs: years.