Evaluation of the electrocardiographic transitional zone by cardiac computed tomography

Tahara, Yoshikazu; Mizuno, Haruyoshi; Ono, Akifumi; Ishikawa, Kinya

doi:10.1016/0022-0736(91)90029-l

Cited by 28 publications

(15 citation statements)

References 7 publications

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“…This data is comparable with a previous study that reported a mean IVS angle from the transverse body axis of 51.8 6 6.8 (Tahara et al, 1991). Taken together, these results imply that the angles for the perpendicular and parallel views of the IVS are around RAO 50 and LAO 40 , respectively, which is also consistent with previous reports (Farr e et al, 2002;Mond et al, 2007;Farr e et al, 2010).…”

Section: Clinical Implications For Procedures Around the Ivssupporting

confidence: 94%

Optimal angulations for obtaining an en face view of each coronary aortic sinus and the interventricular septum: Correlative anatomy around the left ventricular outflow tract

et al. 2015

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An optimal image intensifier angulation used for obtaining an en face view of a target structure is important in electrophysiologic procedures performed around each coronary aortic sinus (CAS). However, few studies have revealed the fluoroscopic anatomy of the target area. This study investigated the optimal angulation for each CAS and the interventricular septum (IVS). The study included 102 consecutive patients who underwent computed tomography coronary angiography. The optimal angle for each CAS was determined by rotating the volume-rendered image around the vertical axis. The angle formed between the anteroposterior axis and IVS was measured using the horizontal section. The frontal direction was defined as zero, positive, or negative if the en face view of the target CAS was obtained in the frontal view, left anterior oblique (LAO) direction, or right anterior oblique (RAO) direction, respectively. The optimal angles for the left, right, and non-CASs were 120.3 ± 10.5°, 4.8 ± 16.3°, and -110.0 ± 13.8°, respectively. The IVS angle was 42.6 ± 8.5°. Accordingly, the optimal image intensifier angulations for the left, right, and non-CASs and the IVS were estimated to be RAO 60°, LAO 5°, LAO 70°, and RAO 50°, respectively. The IVS angle was the most common independent predictor of the optimal angle for each CAS. Differences in the optimal angulations for each CAS and the IVS are demonstrated. The biplane angulation needs to be tailored according to the individual patients and target structures for electrophysiologic procedures.

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Section: Clinical Implications For Procedures Around the Ivssupporting

confidence: 94%

Optimal angulations for obtaining an en face view of each coronary aortic sinus and the interventricular septum: Correlative anatomy around the left ventricular outflow tract

et al. 2015

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“…Previously reported that heart rotation increases with aging due to aortic elongation, but age-related heart rotation may be counteracted by an increase in LV mass index [10]. In this case, the transitional zone of ECG was observed between V4 and V5 indicating clockwise rotation, although there was a weak or no correlation between electrical and anatomical axis in the transverse plane according to some previous reports [11,12]. However, the left ventricle was displaced to the left, and the left-sided angle between the interventricular septum and horizontal axis of the body reduced to 16° by chest CT. We proposed that, in clockwise rotated heart patients, left lateral radiograph was not useful in confirming a true septal location.…”

Section: Discussionsupporting

confidence: 55%

Pacemaker Lead Perforation during Right Ventricular Outflow Tract Pacing -Importance of Heart Rotation at Pacemaker Implantation

Watanabe¹,

Shinoda²,

Ikeoka³

et al. 2016

J Clin Case Rep

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A 70 year-old woman underwent a dual-chamber pacemaker implantation for episodes of transient block and syncope. The transitional zone of her ECG was observed between V4 and V5, indicating clockwise rotation. An experienced physician performed the Right Ventricular Outflow Tract (RVOT) pacing using an active fixation lead without any immediate complications. For RVOT pacing, the lead was placed approximately two-thirds of the distance from the apex to the pulmonary valve in the postero-anterior view and pointing towards the septum in the left anterior oblique view. The ECG revealed a narrow QRS (120 msec) and the lead I morphology was minus-plus. Six days post-implant, a pacemaker interrogation revealed ventricular undersensing and loss of capture with high output pacing. Chest computed tomography revealed the left ventricle was displaced to the left and the left-sided angle between the interventricular septum and horizontal axis of the body was reduced to 16°. It confirmed an RV lead perforation through the RVOT, with 1 cm of the lead positioned outside the heart. We performed a surgical repair. Though ECG and x-rays showed septal pacing, we experienced an unusual case of a subacute myocardial perforation caused by an active fixation lead possibly due to heart rotation. The present case report described a patient with a subacute lead perforation and no hemodynamic instability. It is important for the general cardiologist to pay attention to heart rotation. After implantation, symptoms that can suggest a lead perforation, as major signs such as pericardial effusion are not necessarily present. A pacemaker interrogation shows lower impedance, as well as undersensing or failure to capture the involved chamber in suspicious findings.

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“…The transition zone was the first precordial lead with either an isoelectric QRS or a configuration change from a dominant S (rS) to dominant R (Rs). Clockwise QRS-axis rotation (delayed transition) required R/S transition at or lateral to V4, and counter-clockwise rotation was medial to V3 19. The Minnesota Code defined low voltage and axis deviations 20.…”

Section: Methodsmentioning

confidence: 99%

Mechanisms of ECG signs in chronic obstructive pulmonary disease

et al. 2017

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ObjectivePatients with chronic obstructive pulmonary disease (COPD) often have abnormal ECGs. Our aim was to separate the effects on ECG by airway obstruction, emphysema and right ventricular (RV) afterload in patients with COPD.MethodsA cross-sectional study was performed on 101 patients with COPD without left heart disease and 32 healthy age-matched controls. Body mass index (BMI) was measured, and pulmonary function tests, ECG, echocardiography and right heart catheterisation (only patients) were performed. Variables were grouped into (1) airway obstruction by FEV% (percentage of forced expiratory volume)_predicted, (2) emphysema by residual volume/total lung capacity and residual volume (percent of predicted) and (3) RV afterload by mean pulmonary pressure, artery compliance, vascular resistance and RV wall thickness.ResultsIn multivariate regression analysis, emphysema correlated negatively to R+S amplitudes in horizontal and frontal leads, RV/left ventricle (LV) end-diastolic volume ratio to horizontal amplitudes and BMI negatively to frontal amplitudes. Increased airway obstruction, RV afterload and BMI correlated with horizontal QRS-axis clockwise rotation. Airway obstruction, RV afterload, RV/LV end-diastolic volume ratio and BMI correlated to the Sokolow-Lyon Index for RV, and RV afterload negatively to Sokolow-LyonIndex for LV. Several classical ECG changes could, however, not be ascribed to specific mechanisms.ConclusionsIn COPD, the various pathophysiological mechanisms modify the ECG differently. Increased airway obstruction and RV afterload mainly increase the Sokolow-Lyon Index for RV mass and associate with clockwise rotation of the horizontal QRS-axis, whereas emphysema reduces the QRS amplitudes. BMI is an equally important determinant for the majority of the ECG changes.

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Evaluation of the electrocardiographic transitional zone by cardiac computed tomography

Cited by 28 publications

References 7 publications

Optimal angulations for obtaining an en face view of each coronary aortic sinus and the interventricular septum: Correlative anatomy around the left ventricular outflow tract

Optimal angulations for obtaining an en face view of each coronary aortic sinus and the interventricular septum: Correlative anatomy around the left ventricular outflow tract

Pacemaker Lead Perforation during Right Ventricular Outflow Tract Pacing -Importance of Heart Rotation at Pacemaker Implantation

Mechanisms of ECG signs in chronic obstructive pulmonary disease

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