3 research outputs found
QRS fragmentation: Diagnostic and prognostic significance
Fragmentation of QRS (fQRS) complex is an easily evaluated non-invasive electrocardiographic
parameter. Fragmentation of narrow QRS is defined as presence of an additional R wave (R′)
or notching in the nadir of the S wave, or the presence of > 1 R′ in 2 contiguous leads,
corresponding to a major coronary artery territory on the resting 12-lead ECG. Fragmentation
of wide complex QRS consists of various RSR patterns, with more than 2 R waves (R′′) or
more than 2 notches in the R wave, or more than 2 notches in the downstroke or upstroke of the
S wave. Presence of fQRS has been associated with alternation of myocardial activation due to
myocardial scar and myocardial fibrosis. Initial studies reported higher sensitivity of fQRS
than Q wave for detecting myocardial scar and postulated that the presence of fQRS could be
a good predictor of cardiac events among the patients with coronary artery disease. The
presence of fQRS has been investigated among the patients with ischemic and non-ischemic
cardiomyopathy suggesting that this ECG parameter may affect prognosis and risk of sudden
cardiac death, risk of implantable cardioverter-defibrillator therapy and response to cardiac
resynchronization therapy. In addition, there is evidence that fQRS could play an important
role as screening and prognostic tool among the patients with Brugada syndrome, long QT
syndrome, arrhythmogenic right ventricular dysplasia and cardiac sarcoidosis. This paper
reviews definition, diagnostic and prognostic value of fQRS in different patient populations.
(Cardiol J 2012; 19, 2: 114–121
Review of processing pathological vectorcardiographic records for the detection of heart disease
Vectorcardiography (VCG) is another useful method that provides us with useful spatial information about the electrical activity of the heart. The use of vectorcardiography in clinical practice is not common nowadays, mainly due to the well-established 12-lead ECG system. However, VCG leads can be derived from standard 12-lead ECG systems using mathematical transformations. These derived or directly measured VCG records have proven to be a useful tool for diagnosing various heart diseases such as myocardial infarction, ventricular hypertrophy, myocardial scars, long QT syndrome, etc., where standard ECG does not achieve reliable accuracy within automated detection. With the development of computer technology in recent years, vectorcardiography is beginning to come to the forefront again. In this review we highlight the analysis of VCG records within the extraction of functional parameters for the detection of heart disease. We focus on methods of processing VCG functionalities and their use in given pathologies. Improving or combining current or developing new advanced signal processing methods can contribute to better and earlier detection of heart disease. We also focus on the most commonly used methods to derive a VCG from 12-lead ECG.Web of Science13art. no. 85659