Developments in Conventional Pacing – Harmful Effects of Pacing the Right Ventricular Apex and Strategies to Avoid it

2006 ◽  
Vol 0 (2) ◽  
pp. 1
Author(s):  
Mark C S Hall ◽  
Johan E P Waktare ◽  
◽  
Keyword(s):  
Right Ventricular ◽  
Right Ventricular Apex ◽  
The Right ◽  
Harmful Effects

Recurrent appearance of protective zones after an unsuccessful defibrillation shock

1996 ◽  
Vol 271 (4) ◽  
pp. H1491-H1497 ◽  
Author(s):  
C. Hwang ◽  
W. Fan ◽  
P. S. Chen
Keyword(s):  
Right Ventricular ◽  
Energy Requirement ◽  
Right Ventricular Outflow Tract ◽  
Posterior Wall ◽  
Ventricular Outflow Tract ◽  
Specific Time ◽  
Time Intervals ◽  
Cycle Lengths ◽  
Right Ventricular Apex ◽  
The Right

This study was designed to test the hypothesis that protective zones appear recurrently at the initiation of ventricular fibrillation (VF) and that when shocks are delivered during protective zones, there can be a decrease in the defibrillation energy requirement. A total of 12 open-chest dogs were studied. Six dogs were included in protocol 1. After eight baseline pacing stimuli (S1) with cycle lengths of 300 ms, a strong premature stimulus (S2) (73 +/- 10 mA) was given to induce VF. In subsequent episodes, a second strong premature stimulus (S3) was given at progressively longer S2-S3 intervals in 20-ms increments. In protocol 2, we delivered unsuccessful defibrillation shocks via a transvenous defibrillation electrode placed in the right ventricular apex of six dogs. A second shock was then delivered to patch electrodes on the right ventricular outflow tract and the posterior wall of the left ventricle. The results of protocol 1 showed that the S3 terminated reentry and prevented VF only when it occurred at specific time intervals after the S2 (the protective zones). These protective zones appear recurrently up to 375 ms after the onset of VF. The results of protocol 2 showed that the total energy required for successful defibrillation was dependent on the interval between the first and second shocks. Intervals favoring effective defibrillation (protective zones) appeared recurrently for up to 280 ms after the first shock. When the second shock was delivered during a protective zone, the defibrillation energy requirement was decreased by up to 23% (from 13.1 +/- 2.0 to 10.1 +/- 1.8 J, P < 0.003). However, when the shock was delivered outside the protective zone, a significant increase in the defibrillation energy requirement was observed. We conclude that protective zones appear recurrently at the onset of VF and after unsuccessful defibrillation shocks.

scholarly journals Hypertrophic cardiomyopathy involving the right ventricular apex

2007 ◽  
Vol 23 (14) ◽  
pp. 1162
Author(s):  
Georgios K. Efthimiadis ◽  
Georgios Spanos ◽  
Georgios Giannakoulas
Keyword(s):  
Hypertrophic Cardiomyopathy ◽  
Right Ventricular ◽  
Right Ventricular Apex ◽  
The Right

scholarly journals Alterations in the expression of genes related to contractile function and hypertrophy of the left ventricle in chronically paced patients from the right ventricular apex

EP Europace ◽  
2015 ◽  
Vol 17 (10) ◽  
pp. 1563.1-1570 ◽  
Author(s):  
Eva G. Arkolaki ◽  
Emmanuel N. Simantirakis ◽  
Joanna E. Kontaraki ◽  
Stavros I. Chrysostomakis ◽  
Alexandros P. Patrianakos ◽  
...  
Keyword(s):  
Left Ventricle ◽  
Right Ventricular ◽  
Contractile Function ◽  
Expression Of Genes ◽  
Right Ventricular Apex ◽  
The Right

scholarly journals P706 LMCA and LAD coronary ectasia in an asymptomatic young patient reassessment with multimodality imaging after 17 years

2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
E Ayduk ◽  
P Karaca Ozer ◽  
M Dursun ◽  
S Umman ◽  
Y C Toktas ◽  
...  
Keyword(s):  
Pulmonary Artery ◽  
Right Ventricle ◽  
Right Ventricular ◽  
Thrombus Formation ◽  
Color Doppler ◽  
Color Doppler Echocardiography ◽  
Cystic Structure ◽  
Right Ventricular Apex ◽  
Septal Branch ◽  
The Right

Abstract A 25 years old male patient was referred to an advanced center because of 2/6-degree systolo-diastolic murmur heard at meso-cardiac area during his pre-military routine examination. ECG revealed T wave inversions at standard D1 to D3 and precordial V1 to V4 leads, treadmill was non-diagnostic for ischemia. In his transthoracic echocardiogram, measurement of heart chambers and wall thicknesses were within normal range with normal wall motion of the left ventricle, EF was 55%. 2D and color-Doppler echocardiography revealed a cystic structure with venous flow in it at the right ventricular apex, and created a suspicion of a fistula. Myocardial perfusion scintigraphy showed ischemia at the apical sections of the septal wall. He underwent coronary angiography, LMCA and proximal LAD were ectatic, LAD ectasia was in consistent with the first septal branch, circumflex (Cx) and right coronary artery (RCA) angiograms were normal. LAD flow was examined and no fistula was detected. Right and left ventriculography revealed normal ventricular functions, oxygen saturations were 70.9% in pulmonary artery, 70.4% in right ventricle, 72.9% in right atrium, and 97.4% in the aorta. Pulmonary capillary wedge pressure was 10 mmHg, pulmonary artery pressure 10/26/5 mmHg, right ventricular pressure 13/6 mmHg, left ventricular pressure 120/0/8 mmHg. Further investigations for etiology and congenital malformations were planned and the patient was discharged with oral anticoagulant therapy. The patient had no contact with the outpatient clinic for 17 years. At the 17th year of the diagnosis he was called and reevaluated. He was still asymptomatic and oscultation findings were the same. Transthoracic 2D and 3D and color-Doppler echocardiography revealed the same cystic structure at the right ventricular apex, but this time with no-flow. Coronary CT angiography was performed, LMCA was ectatic and the diameter was 8.1 mm, proximal LAD was ectatic and the diameter was 6 mm, ectasia was in continuous with the first septal branch. The ectatic septal branch was at the apical level of the right ventricle, appearing like a cystic structure with a diameter of 2.8 cm, and the lack of contrast enhancement was thougt to be in consistent with thrombus formation. Cx and RCA artery calibrations were found to be normal. In order to confirm the diagnosis of thrombus formation, MR angiography was performed. Perfusion MRI showed no evidence of thrombus in the ectatic septal branch. Abstract P706 Figure.

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