Regional and Temporal Variation of Ventricular and Conduction Tissue Activity During Ventricular Fibrillation in Canines

2021 ◽  
Author(s):  
Nicholas Tan ◽  
Georgios Christopoulos ◽  
Thomas P. Ladas ◽  
Zhi Jiang ◽  
Alan M. Sugrue ◽  
...  
Keyword(s):  
Ventricular Fibrillation ◽  
Left Ventricle ◽  
Electrical Activity ◽  
Cycle Length ◽  
Time Interval ◽  
Apical Region ◽  
Free Wall ◽  
Purkinje System ◽  
Regularity Index ◽  
Rigorous Study

Background: Rigorous study of ventricular fibrillation (VF) is not feasible in humans. The spatiotemporal characteristics of prolonged VF remain undefined, limiting our understanding of this lethal rhythm. Methods: VF was mapped in 4 canines. The endocardial and epicardial left ventricle (LV) and right ventricle (RV) were sequentially mapped at 0 to 15, 15 to 30, 30 to 45, and 45 to 60 minutes post-induction. Ten consecutive beats were used to determine average cycle length and regularity index of ventricular and His-Purkinje system signals in discrete regions during each time interval. Results: Average VF time was 58±12 minutes. The shortest ventricular cycle length was present in the RV apical region (70±10 msec) at 0 to 15 minutes and at 15 to 30 minutes (89±31 msec) and LV apical region at 45 to 60 minutes (242±163 msec). The His-Purkinje system cycle length was the shortest at the RV outflow tract (75±3 msec) at 0 to 15 minutes, RV inflow and free wall (89±12 msec) at 15 to 30 minutes, LV apical region (83±14 msec) at 30 to 45 minutes, and inferior and inferolateral LV (145±23 msec) at 45 to 60 minutes. Regularity index was the highest in the RV inflow and free wall (78%) at 0 to 15 minutes, RV apical region (86%) at 15 to 30 minutes, LV septum and epicardial anterior RV (80%) at 30 to 45 minutes, and anterior and anterolateral LV (75%) at 45 to 60 minutes. Conclusions: These data suggest significant regional changes in electrical activity throughout VF in canines. A transition of fastest electrical activity from RV to LV apical regions across VF was observed. Further studies are warranted to confirm the above findings.

Is there a correlation between ventricular fibrillation cycle length and electrophysiological and anatomic properties of the canine left ventricle?

2004 ◽  
Vol 287 (2) ◽  
pp. H823-H832
Author(s):  
Taresh Taneja ◽  
George Horvath ◽  
Darlene K. Racker ◽  
David Johnson ◽  
Jeffrey Goldberger ◽  
...  
Keyword(s):  
Ventricular Fibrillation ◽  
Left Ventricle ◽  
Cycle Length

Purkinje involvement in arrhythmias after coronary artery reperfusion

2002 ◽  
Vol 282 (4) ◽  
pp. H1189-H1196 ◽  
Author(s):  
David O. Arnar ◽  
James B. Martins
Keyword(s):  
Ventricular Tachycardia ◽  
Coronary Artery ◽  
Ventricular Fibrillation ◽  
Cycle Length ◽  
Ischemic Myocardium ◽  
Risk Zone ◽  
Purkinje System ◽  
Mean Cycle

Previous studies have indicated that the endocardium may be responsible for a large portion of ventricular tachycardia (VT) seen with reperfusion of ischemic myocardium. To evaluate the role of the Purkinje system in nonreentrant VT arising from the endocardium after reperfusion, the anterior descending coronary artery was occluded for 20 min and then reperfused in 23 dogs after instrumentation of the risk zone with 21 multipolar plunge needles. VT with focal Purkinje origin was defined as a focal endocardial VT with Purkinje potentials recorded before the earliest endocardial myopotential. A total of 19 VTs (mean cycle length 214 ± 2 ms) were observed with 11 (58%) having focal Purkinje origin. Fifty-eight percent of the VTs degenerated to ventricular fibrillation, with occurrences of two or more independent foci per complex (seen in 7 of 11 compared with 1 of 8 nonsustained VTs). In conclusion, these data show that Purkinje tissue may be important in the genesis of reperfusion VT.

Abstract 052: Improved Hospital Outcomes With Hypokalemia on Admission in Cardiac Arrest Survivors Treated With Therapeutic Hypothermia

2017 ◽  
Vol 10 (suppl_3) ◽  
Author(s):  
Angelo de la Rosa ◽  
Manuel Tapia ◽  
Yong Ji ◽  
Basil Saour ◽  
Mikhail Torosoff
Keyword(s):  
Logistic Regression ◽  
Cardiac Arrest ◽  
Ventricular Fibrillation ◽  
Hospital Mortality ◽  
Electrical Activity ◽  
Therapeutic Hypothermia ◽  
Multivariate Logistic Regression Analysis ◽  
Pulseless Electrical Activity ◽  
Older Age ◽  
Chi Square

Purpose: We hypothesized that advanced circulatory compromise, as manifested by acidosis and hyperkalemia should be associated with worsened clinical outcomes in cardiac arrest patients treated with therapeutic hypothermia. Methods: Results of initial admission laboratory studies, medical history, and echocardiogram in 203 consecutive cardiac arrest patients (59 females, 59+/- 15 years old) undergoing therapeutic hypothermia were reviewed. Mortality was ascertained through hospital records. ANOVA, chi-square, Kaplan-Meier, and logistic regression analyses were used. The study was approved by the institutional IRB. Results: Increased mortality was noted with older age, decreased admission pH, elevated admission lactate, lower admission hemoglobin, and pulseless electrical activity or asystole as presenting rhythms (Table). Admission hypokalemia and ventricular fibrillation/tachycardia were associated with improved hospital mortality (Table). Potassium was significantly lower in patients admitted with ventricular fibrillation/tachycardia (3.897+/-0.92) as compared to patients with asystole (4.674+/-1.377) or pulseless electrical activity (4.491+/-1.055 mEq/dL, p<0.0001). In multivariate logistic regression analysis, independent predictors of increased hospital mortality included increased admission potassium (OR 2.0, 95%CI 1.291-3.170, p=0.002)), older age (OR 1.04, 95%CI 1.007-1.071, p=0.017), admission PEA (OR 3.7, 95%CI 1.358-10.282, p=0.011 when compared to ventricular fibrillation/tachycardia) or asystole (OR 17.2, 95%CI 4.423-66.810, p<0.001 when compared to ventricular fibrillation/tachycardia); while decreased mortality was associated with higher hemoglobin (OR 0.8, 95%CI 0.665-0.997, p=0.047). Conclusions: Hyperkalemia, pulseless electrical activity, and asystole are predictive of increased hospital mortality in survivors of cardiac arrest. An association between low or low-normal potassium, observed VT-VF, and better outcomes is unexpected and may be used for prognostic purposes. More prospective investigations of mortality predictors in these critically ill patients are needed.

Abstract 15002: Towards Unmasking Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy in the Early Concealed Stage

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Thomas P Mast ◽  
Arco J Teske ◽  
Jeroen F vd Heijden ◽  
Judith A Groeneweg ◽  
Pieter A Doevendans ◽  
...  
Keyword(s):  
Right Ventricular ◽  
Arrhythmogenic Right Ventricular Dysplasia ◽  
Tissue Doppler ◽  
Doppler Imaging ◽  
Apical Region ◽  
Free Wall ◽  
Right Ventricular Dysplasia ◽  
Mutation Carriers ◽  
Increased Risk ◽  
Repolarization Abnormalities

Background: The concealed stage of arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is associated with increased risk of sudden cardiac death. However, particular at this stage disease detection is hampered by absence of criteria. Activation delay (AD) is a hallmark of arrhythmogenesis in ARVD/C. Echocardiographic tissue Doppler imaging (TDI) may unmask AD in the absence of electrocardiographic (ECG) abnormalities. Methods: Three groups were compared 1) symptomatic definite ARVD/C patients with a mutation in the Plakophilin-2 ( PKP2) gene (n=37), 2) asymptomatic PKP2 mutation carriers (n=20) and 3) healthy controls (n=30). All groups underwent full echocardiographic examination with additional TDI of the right ventricular (RV) free wall and a routine 12-lead ECG recording. As surrogate for AD the electro-mechanical interval (EMI) was measured, defined as time between local first electrical deflection and local onset of mechanical shortening. EMI was measured in the subtricuspid, mid and apical region of the RV free wall. Detailed ECG analysis of depolarization (AD analysis) and repolarization abnormalities was performed in all subjects. Results: EMI was prolonged in all RV segments in ARVD/C patients compared to controls. Abnormal depolarization and repolarization was recorded in respectively 23 and 27 ARVD/C patients. In asymptomatic mutation carriers EMI was significantly prolonged in the subtricuspid area (Table 1). However, the ECG showed in 5/20 subjects only prolonged terminal activation duration and no repolarization abnormalities. Conclusion: TDI unmasks AD in both ARVD/C patients and asymptomatic mutation carriers. In asymptomatic mutation carriers EMI is prolonged in the subtricuspid area, whereas ECG appeared normal in the large majority. AD in the subtricuspid area is an early sign of disease in the concealed ARVD/C stage and may contribute to advanced risk stratification. Table 1: Results

Ventricular systolic interdependence: volume elastance model in isolated canine hearts

1987 ◽  
Vol 253 (6) ◽  
pp. H1381-H1390 ◽  
Author(s):  
W. L. Maughan ◽  
K. Sunagawa ◽  
K. Sagawa
Keyword(s):  
Left Ventricle ◽  
Right Ventricle ◽  
Cross Talk ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Ventricular Free Wall ◽  
Free Wall ◽  
Right Ventricular Free Wall ◽  
Systolic Volume ◽  
The Right

To analyze the interaction between the right and left ventricle, we developed a model that consists of three functional elastic compartments (left ventricular free wall, septal, and right ventricular free wall compartments). Using 10 isolated blood-perfused canine hearts, we determined the end-systolic volume elastance of each of these three compartments. The functional septum was by far stiffer for either direction [47.2 +/- 7.2 (SE) mmHg/ml when pushed from left ventricle and 44.6 +/- 6.8 when pushed from right ventricle] than ventricular free walls [6.8 +/- 0.9 mmHg/ml for left ventricle and 2.9 +/- 0.2 for right ventricle]. The model prediction that right-to-left ventricular interaction (GRL) would be about twice as large as left-to-right interaction (GLR) was tested by direct measurement of changes in isovolumic peak pressure in one ventricle while the systolic pressure of the contralateral ventricle was varied. GRL thus measured was about twice GLR (0.146 +/- 0.003 vs. 0.08 +/- 0.001). In a separate protocol the end-systolic pressure-volume relationship (ESPVR) of each ventricle was measured while the contralateral ventricle was alternatively empty and while systolic pressure was maintained at a fixed value. The cross-talk gain was derived by dividing the amount of upward shift of the ESPVR by the systolic pressure difference in the other ventricle. Again GRL measured about twice GLR (0.126 +/- 0.002 vs. 0.065 +/- 0.008). There was no statistical difference between the gains determined by each of the three methods (predicted from the compartment elastances, measured directly, or calculated from shifts in the ESPVR). We conclude that systolic cross-talk gain was twice as large from right to left as from left to right and that the three-compartment volume elastance model is a powerful concept in interpreting ventricular cross talk.

Regional variations in calculated diastolic wall stress in rat left ventricle

1978 ◽  
Vol 235 (2) ◽  
pp. H247-H250 ◽  
Author(s):  
L. Role ◽  
D. Bogen ◽  
T. A. McMahon ◽  
W. H. Abelmann
Keyword(s):  
Heart Disease ◽  
Left Ventricle ◽  
Significant Variation ◽  
Diastolic Pressure ◽  
Wall Stress ◽  
Free Wall ◽  
Predisposing Factor ◽  
Rat Hearts ◽  
The Mean ◽  
Apical Aneurysm

Principal radii of curvature and wall thickness were measured at the apex and three other loci on the free wall of the left ventricle in 16 rat hearts that had been fixed at end-diastolic pressure. The law of Laplace was applied to calculate the mean tensile stress at each locus. No significant variation was found among the nonapical loci, but apical stress was approximately twice the stress calculated for any nonapical locus. The higher stresses that must be borne by the apex may be a predisposing factor for apical aneurysm in certain cardiomyopathies such as Chagas' disease. These higher stresses may also help to promote apical aneurysms in patients with ischemic heart disease.

scholarly journals Spiral wave unpinning facilitated by wave emitting sites in cardiac monolayers

2019 ◽  
Vol 475 (2230) ◽  
pp. 20190420
Author(s):  
Shreyas Punacha ◽  
Sebastian Berg ◽  
Anupama Sebastian ◽  
Valentin I. Krinski ◽  
Stefan Luther ◽  
...  
Keyword(s):  
Electric Field ◽  
Electrical Activity ◽  
Spiral Wave ◽  
Electrical Stimulus ◽  
Spiral Waves ◽  
Time Interval ◽  
Field Pulse ◽  
The Core ◽  
Rotating Wave ◽  
Multiple Obstacles

Rotating spiral waves of electrical activity in the heart can anchor to unexcitable tissue (an obstacle) and become stable pinned waves. A pinned rotating wave can be unpinned either by a local electrical stimulus applied close to the spiral core, or by an electric field pulse that excites the core of a pinned wave independently of its localization. The wave will be unpinned only when the pulse is delivered inside a narrow time interval called the unpinning window (UW) of the spiral. In experiments with cardiac monolayers, we found that other obstacles situated near the pinning centre of the spiral can facilitate unpinning. In numerical simulations, we found increasing or decreasing of the UW depending on the location, orientation and distance between the pinning centre and an obstacle. Our study indicates that multiple obstacles could contribute to unpinning in experiments with intact hearts.

scholarly journals Successful Surgical Treatment of Postinfarction Rupture of Left Ventricular Myocardium

2020 ◽  
Vol 9 (1) ◽  
pp. 140-147
Author(s):  
M. K. Mazanov ◽  
N. I. Kharitonova ◽  
A. A. Baranov ◽  
S. Yu. Kambarov ◽  
N. M. Bikbova ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Left Ventricle ◽  
Surgical Intervention ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Left Ventricular Myocardium ◽  
Free Wall ◽  
Fatal Complication ◽  
Widespread Availability ◽  
Complications Of Myocardial Infarction

ABSTRACT. The rupture of the left ventricle free wall is one of the most dangerous complications of myocardial infarction. Due to the widespread availability of echocardiography method, the detection of this fatal complication and the number of lives saved after surgery grew. The survival of patients depends on early diagnosis, stabilization of the patient’s condition, promptness and tactics of surgical intervention. We report a case of successful closure of a rupture of the left ventricle free wall on the 15th day after myocardial infarction.

LEFT VENTRICLE FREE WALL MASS LOSS IN A MONOCROTALINE INDUCED PULMONARY HYPERTENSION RAT MODEL

2018 ◽  
Vol 71 (11) ◽  
pp. A1950
Author(s):  
Mateusz Holda ◽  
Jakub Holda ◽  
Kamil Tyrak ◽  
Grzegorz Kopec ◽  
Piotr Podolec
Keyword(s):  
Pulmonary Hypertension ◽  
Left Ventricle ◽  
Mass Loss ◽  
Rat Model ◽  
Free Wall ◽  
Wall Mass
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