الفهرس 
Congenital Heart Diseases (CHDs)
Pathophysiology of PAH-CHD:Only 14 pages are availabe for public view
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Abstract
Pulmonary arterial hypertension (PAH) defined as increase in pulmonary artery pressure more than 25 mmHg as rest assessed by right heart catheterization, is a freque complication of congenital heart disease (CHD), particularly
in patients with left-to-right shunts, as persistent exposure of pulmonary vasculature to increased blood flow and pressure results in vascular remodeling and dysfunction. Cardiac arrhythmias are important contributors to morbidity and mortality rate in patients with PAH-CHD, hence, evaluation and early detection of arrhythmias in this patient
group is of crucial importance during clinical follow-up. In addition to careful history and physical examination, more comprehensive invasive and non-invasive investigations are necessary. For example, electrcardiographic (ECG) indices; QTc, QTd, PWd, heart rate variability (HRV) and 24-Holter monitor are all non-invasive modalities for detecting predisposition to arrhythmias. QT dispersion (QTd) is the difference between the maximum QT duration and minimum QT duration in different leads of 12-lead ECG tracing; QT duration is being the interval from the onset point of QRS complex till the offset of T wave. P-wave dispersion (PWd) is the difference between the
maximum and the minimum P-wave duration recorded from multiple different surface ECG leads. Both ECG indices are
reported to be almost direct measures of heterogeneity of myocardial repolarization and inter-atrial conduction abnormalities, and intensively investigated as non-invasive
parameters that carry a strong predictive value for arrhythmia
in PAH patients.