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Keywords:
Cardiac, CT-Angiography, Computer Applications-Detection, diagnosis, Ischaemia / Infarction, Congenital
Authors:
A. G. Allam; Doha/QA
DOI:
10.1594/ecr2016/C-2014
Aims and objectives
Myocardial bridging is a congenital anomaly in which a segment of a coronary artery takes a “tunneled” intramuscular course under a “bridge” of overlying myocardium.
This may cause vessel compression in systole,
resulting in haemodynamic changes that may be associated with angina,
myocardial ischaemia,
acute coronary syndrome,
left ventricular dysfunction,
arrhythmias,
and even sudden cardiac death [1].
Myocardial bridging,
first described anatomically by Reyman in 1737 [2] is a congenital variant of a coronary artery in which a portion of an epicardial coronary artery (most frequently the middle segment of the left anterior descending artery,
LAD) takes an intramuscular course [3].
This arrangement of a “tunneled” segment of the artery under the “bridge” of overlying myocardium can result in vessel compression during systole.
While frequently asymptomatic,
this condition in many cases may be responsible for adverse complications including angina,
myocardial ischaemia [4],
acute coronary syndromes [5-7],
left ventricular dysfunction,
arrhythmias [8-10] and even sudden cardiac death [11].
This anomaly is more frequently seen in patients with hypertrophic cardiomyopathy; the prevalence rating is up to 30% on coronary angiography [12].
The anomaly is also seen with increased prevalence in patients who have undergone heart transplantation [13].
The real prevalence of myocardial bridging is still unknown,
ranging from 0.5% to 4.9% in angiographic series and from 15% to 85% in autopsies [14].
Since Multidetector Computed Tomography (MDCT) has been widely used for the non-invasive evaluation of coronary artery disease (CAD) radiologists have encountered myocardial bridging more frequently than previously reported [15].
Konen et al [16} defined three useful anatomical patterns of myocardial bridging in the LAD according to the depth and course of the tunneled segment on MDCT: the “superficial” type seen in 29% of all intramuscular LAD segments,
in which the tunneled segment had a superficial course along the interventricular LAD septum and was covered by a thin layer of tissue (<1mm thick); the “deep” type,
seen in 41% of all tunneled LAD segments,
in which the tunneled segment penetrated the interventricular septum at a depth between 1 and 6.2mm; and the “right ventricular” type,
seen in 29% of all tunneled LAD segments,
in which the tunneled segment crossed through the right ventricular anterior wall adjacent to the interventricular septum.
Purpose:
The aim of the study is to evaluate the patients diagnosed with myocardial bridging by Computerised tomographic angiography (CTA) over a three and a half year period in our centre.