Table 2.
Cardiovascular assessment of PACE participants
| Imaging study | Procedure | Measures collected | Definitions/Analyses |
|---|---|---|---|
| Signal-Averaged Electrocardiogram (SAECG), orthogonal ECG and 12 Lead ECG | Recorded using standard 12 and Frank orthogonal XYZ leads during a minimum of 5 minutes at rest with a 1000 Hz sampling frequency and high-pass filter 0.05 Hz and low pass filter 350 Hz. | 12 Lead ECG: Heart rate rhythm | Sinus rhythm, tachy/bradycardia |
| PC ECG machine (Norav Medical Ltd, Thornhill, ON, Canada) and Marquette ECG* (GE Medical Systems, Milwaukee, WI) | Signal Averaged ECG: Ventricular late potentials | Ventricular late potentials considered positive with 2 or more criteria: (1) fQRSd >114 ms, (2) LAS-40 > 38 ms, and (3) RMS-40 < 20 μV, where fQRSd is total filtered QRS duration; LAS-40 is duration of the low-amplitude signals (<40 mV) in the terminal portion; and RMS-40 is root mean square voltage of the last 40 ms. | |
| Corrected QT interval QT variability index (QTVI) | QTc > 0.44 QTVI > −0.5 | ||
| Heart Rate Variability | SDNN < 50 ms HRV Index < 15 LF/HF > 1.5 | ||
| Multidetector Computed Tomography (CT) and Angiography (CTA) | Prospective electrocardiographic gating with gantry rotation times 350–400 msec. Scans triggered by electrocardiography signal at 70-80% RR interval, near the end of diastole, and before atrial contractions, to minimize the effect of cardiac motion. Conducted with IV visipaque contrast if not contraindicated and metoprolol if heart rate greater than 70 beat per minute. | Left main (LM) Left anterior descending (LAD) Left anterior descending (LAD) Left circumflex (LCX) Right coronary artery (RCA) | Coronary vessel stenosis defined as significant narrowing (50% or more diameter reduction) of the lumen. |
| Toshiba Aquilon 32 (Toshiba, Japan) | Coronary calcium score Valvular calcium | Coronary calcium determined using Agatston score. Valvular calcium is measured. | |
| Echocardiogram | Conducted in a reclined position with 4 chamber views and M mode echocardiography to determine left ventricular and atrial dimensions | Ejection fraction (EF) | EF = (EDV-ESV / EDV) x100% |
| Toshiba Artida, (Toshiba, Japan) | Aortic root pulmonary arterial pressure | Aortic root normal parameters = 0.6-1.1Cm tricuspid regurgitation pressures | |
| LV mass index* | LV mass = 0.8 (1.04 ([LVIDD + PWTD + IVSTD]3- [LVIDD]3)) + 0.6 g | ||
| Pulse wave velocity | Measures are performed supine after 5 minutes of rest using the right carotid and right femoral arteries. The operator captures 10 seconds of stable waveform and repeats the sequence using the femoral artery. The computer generated aortic PWV with a standard deviation is reviewed. | Carotid-femoral pulse wave velocity | |
| Sphygmocor PVx system (Atcor Medical, Australia) | |||
| Pulse wave analysis | Measures are performed supine after 5 minutes of rest using the right radial artery (left radial artery if right access is dialysis access present). The operator captures 10 seconds of stable waveform. The computer generated quality indices and operator index are reviewed. | Systolic central aortic pressure Diastolic central aortic pressure Mean central aortic pressure aortic Augmentation index | |
| Sphygmocor PVx system (Atcor Medical, Australia) | |||
| Ankle Brachial Index (ABI) | Measures are performed after 5 minutes of rest in a supine position and assessed by measuring blood pressure bilaterally in the brachial, dorsalis pedis and posterior tibial arteries. | Right brachial pressure right posterior tibial artery (PTA) right dorsalis pedis artery (DPA) left brachial pressure left posterior tibial artery (PTA) left dorsalis pedis artery (DPA) | Right ABI = Higher of the right ankle pressures (PT or DP)/ Higher arm pressure (right or left) Left ABI = Higher of the left ankle pressures (PT or DP)/ Higher arm pressure (right or left) |
| Doppler probe |
*by Devereux formula; LVIDD = Left Ventricular Internal Diameter in Diastole, PWTD = Posterior Wall Thickness in Diastole, IVSTD = Interventricular Septum Thickness in Diastole.