Page 58 - The role of advanced echocardiography in patients with ischemic heart disease - Rachid Abou

Chapter three. Age related left atrial remodeling
were stored at the departmental Cardiology Information System (EZIS chipsoft and EPD-Vision®, Leiden University Medical Center). The Dutch Central Committee on Human-related Research (CCMO) allows the use of anonymous data without prior approval of an institutional review board provided that the data is acquired for routine patient care. All data used for this study was acquired for clinical purposes and handled anonymously.
The standard 12-lead ECG was recorded at 100 mm/s paper speed and 40 mm/mV calibration. Customized software was used to analyse the PWD (Megacare Infinity VF4, Dräger Medical, Danvers MA, USA). PWD was defined as the time difference between maximum P-wave duration and minimum P-wave duration measured in any lead (Figure 1). The onset and end of the P-wave were defined as the point of the first visible upward slope from the isoelectric line and the point of return to isoelectric line, respectively. QT interval was corrected for heart rate using the Bazett formula: QTc=QT/√R–R.12
Figure 1. P-wave dispersion measured on 12-lead ECG. Panel A shows a full cardiac cycle in lead I obtained from a standard 12-lead ECG. Panel B is an enlargement of the box plotted in section
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