scholarly journals ECG and Pacing Criteria for Differentiating Conduction System Pacing from Myocardial Pacing

2021 ◽  
Vol 10 (3) ◽  
pp. 172-180
Author(s):  
Marek Jastrzębski

During His-Purkinje conduction system (HPS) pacing, it is crucial to confirm capture of the His bundle or left bundle branch versus myocardialonly capture. For this, several methods and criteria for differentiation between non-selective (ns) capture – capture of the HPS and the adjacent myocardium – and myocardial-only capture were developed. HPS capture results in faster and more homogenous depolarisation of the left ventricle than right ventricular septal (RVS) myocardial-only capture. Specifically, the depolarisation of the left ventricle (LV) does not require slow cell-to-cell spread of activation from the right side to the left side of the interventricular septum but begins simultaneously with QRS onset as in native depolarisation. These phenomena greatly influence QRS complex morphology and form the basis of electrocardiographic differentiation between HPS and myocardial paced QRS. Moreover, the HPS and the working myocardium are different tissues within the heart muscle that vary not only in conduction velocities but also in refractoriness and capture thresholds. These last two differences can be exploited for the diagnosis of HPS capture using dynamic pacing manoeuvres, namely differential output pacing, programmed stimulation and burst pacing. This review summarises current knowledge of this subject.

2021 ◽  
Vol 4 (5) ◽  
pp. 01-13
Author(s):  
Avra Laarakker

Objective: We report a case of self inserted needle into the left ventricle of the heart and a description of our surgical intervention in a psychiatric patient without decision-making capacity. We discuss issues regarding obtaining consent in this patient with a sub-acute presentation, report our operative approach, and summarize a treatment approach based on a review of current literature. Methods: A PubMed search using terms “needle, “heart”, “insertion”, “intracardiac foreign object”, yielded 69 relevant papers. 67 of these were case reports yielding 72 individual cases. Age, gender, cause of the needle entry (Accidental Plus (A+), Intravenous Drug User [IVDU], Self-inflicted (SI)), type of needle, location in heart, neuropsychiatric history, treatment, and outcome were documented. Results: Within the SI category, there were a total of 28 cases, 89.3% had a neuropsychiatric history whereas only there were only 2 such patients in both the IVDU and A+ group. The location of the needle in the heart in all 72 cases was as follows: right ventricle 40.3%, other 20.8%, left ventricle 19.4 %, ventricle and interventricular septum 16.7% and the right and left atrium were each 1.4 %. In all three groups (n=72), 77.8% of patients underwent surgery, with 92.9% having a stable outcome. Conclusion: Our case and review demonstrates that management of such cases, particularly when active mental health issues are present, requires a case-by-case evaluation and treatment as a specific standard of care has not been established. Surgical intervention appears to be the preferred management regardless of presentation with good outcomes. Running Title: Intracardiac Self Insertion of a Darning Needle in a Psychiatric Patient


1976 ◽  
Vol 231 (3) ◽  
pp. 781-785 ◽  
Author(s):  
OM Brown

The distribution of acetylcholine (ACh) in the cat heart was investigated by a pyrolysis-gas chromatography (PGC) method. The hearts were dissected into various regions and homogenized in acetonitrile in the presence of propionylcholine, internal standard. Following extraction with toluene and hexane, the choline esters were precipitated as the enneaiodide complex. The isolated choline esters were analyzed by PGC, and the peak corresponding to ACh was quantified. The compound extracted from heart tissue that eluted with the retention time of authentic ACh was identified by mass spectrometry as dimethylaminoethylacetate, the pyrolysis product of ACh. ACh concentrations were found to be higher in the atria than the ventricles. In both the atria and the ventricles, a higher content of ACh was found in the right than the left portions: right ventricle, 5.0 compared to left ventricle, 2.0 nmol/g; and right atrium, 16.8 compared to left atrium, 11.3 nmol/g. Some cats were subjected to a bilateral cervical vagotomy 3 wk before removal and analysis of heart tissue. Hearts from vagotomized cats contained less ACh than controls in the right ventricle (-31%), right atrium (-54%), SA node (-42%), and papillary muscle (-53%), but no decreases were found in the left ventricle, left atrium, or interventricular septum.


1961 ◽  
Vol 200 (2) ◽  
pp. 223-228 ◽  
Author(s):  
Robert L. Hamlin ◽  
Allen M. Scher

The pathways of ventricular excitation in the interventricular septum and the free walls of the ventricles were determined in the goat. During the first 5 msec. of the QRS complex, activity occurs in a cup-shaped zone formed around the apex of the left ventricular cavity, consisting of the left endocardial portions of the septum and the endocardium of the free wall. Within the next 10 msec. of the QRS, the apical third of the septum is excited, simultaneously, from both the left and the right ventricular endocardial surfaces. Also, all of the ventricles, except the bases and a small epicardial apical area of the left ventricle, are excited with almost a single burst of depolarization. During the next 3–5 msec. the ventricular bases and the small apical epicardial area are excited along with the middle third of the interventricular septum. The final 15 msec. of the QRS and approximately 3 msec. of the following isoelectric period are inscribed during activation of the basilar third of the septum.


2019 ◽  
Vol 19 (1-2) ◽  
pp. 65-69
Author(s):  
A. I Miroshnichenko ◽  
K. M Ivanov

Actuality. Arterial hypertension (AH) is the main risk factor for the development of cardiovascular diseases, disability and cardiovascular mortality. Episodes of blood pressure (BP) increase during the day in patients receiving antihypertensive therapy are an unfavourable factor contributing to the development and progression of cardiac remodeling. Aim. The purpose of the research is to study the features of changes in the structural and functional state of the heart under the influence of high blood pressure at night in patients with arterial hypertension with the dynamic three-year observation. Material and methods. 47 patients with the diagnosis of AH were examined. Patients were divided into two groups, randomized by age, duration and severity of AH. Group 1 included 24 patients who as a result of ambulatory blood pressure monitoring (ABPM) on the background of combined antihypertensive therapy suffered from constantly increased BP at night. The second group combined 23 patients without the increase in BP during the night according to the ABPM with antihypertensive therapy. The examination included measurement of the office BP, ABPM, two-fold echocardiography with a three-year interval. Results. When assessing the indices of office BP in the groups, there were no significant differences, all patients achieved the target values of BP. In patients in Group 1, higher values of BP were observed during the day, according to ABPM. Echocardiography over a three year period of observation revealed a more pronounced increase in diastolic interventricular septum thickness, the thickness of the left ventricle posterior wall during diastole, sizes of left atrium in the patients of the first group, patients of the second group had a more pronounced thickness of the left ventricle posterior wall during systole. The increase in the size of the right ventricle was revealed in both groups. Conclusions. 1) In patients with the increase in blood pressure at night, the values of BP variability were higher during the day. 2) Three-year dynamic observation revealed that the increase in BP at night in patients with hypertension facilitated acceleration of cardiac remodelling and was associated with an increase in the left ventricular posterior wall, interventricular septum thickness, the size of the left atrium, and the size of the right ventricle.


1959 ◽  
Vol 14 (3) ◽  
pp. 417-420 ◽  
Author(s):  
Philip Samet ◽  
William H. Bernstein ◽  
Robert S. Litwak ◽  
William H. Meyer ◽  
Louis Lemberg

Dissociation of electrical and mechanical asynchronism in the right and left ventricle of the dog has been studied by simultaneous registration of the precordial electrocardiogram and right and left ventricular pressure curves. Observations were made during sinus rhythm and during digitalis-induced ventricular premature beats with widened aberrant QRS complexes. Measurements were made of the time of onset of isometric contraction in the ventricles, relative to each other, and to the onset of the QRS complex. The results indicate that mechanical asynchronism in onset of isometric contraction is not a necessary consequence of the asynchronous electrical depolarization of ventricular premature systoles. Submitted on November 10, 1958


PEDIATRICS ◽  
1970 ◽  
Vol 46 (1) ◽  
pp. 25-27
Author(s):  
William J. Garrett ◽  
David E. Robinson

In the course of routine, two-dimensional ultrasonic echoscopy, echograms have been obtained which show the outline of the fetal heart and interventricular septum. Measurements of the echograms show the fetal heart to occupy 21% of the cross-sectional area of the chest at its widest transverse diameter and to occupy 52% of the transverse diameter of the chest at the same level. The ratio of the tranverse diameter of the left ventricle to that of the right (L.V. ÷ R.V.) is 1.23. The fetal heart grows at the same rate as the fetal chest in the last 8 weeks of pregnancy.


2013 ◽  
Vol 15 (1) ◽  
pp. 10 ◽  
Author(s):  
Majdi Halabi ◽  
Kanishka Ratnayaka ◽  
Anthony Z Faranesh ◽  
Michael S Hansen ◽  
Israel M Barbash ◽  
...  

2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
A M De Roberto ◽  
A Del Pasqua ◽  
M Chinali ◽  
P Francalanci ◽  
C Esposito ◽  
...  

Abstract We report a case of a three months old baby, with no history of heart disease, referred to our center for cardiological screening. EKG was normal and a physiologic 1/6 systolic murmur was present. Conversely, echocardiography revealed a thin-walled, echo-free cystic intrapericardic structure adjacent to the posterior wall of the left ventricle; no signs of compression on cardiac structures were evident. CAT scan confirmed the presence of echo-free cystic over-diaphragmatic structure at the crux cordis level. The cyst was described as located between visceral pericardial layer and muscolar ventricular wall and appeared to cause compression on the midbasal wall of the left ventricle, of the interventricular septum and less extensively on the right ventricle. The dimension of the cyst was 2.7x2.5x1.8 cm. Worthy of note, posterior interventricular and posterolateral coronary arteries were very close to the cyst and partially pushed apart one from the other by the mass. Eight months after the diagnosis we detected an increase in mass size, confirmed also by cardiac MRI showing a mass of 4.5x3.4x3 cm with an extimated volume of 23 cm2. Because of significant increase of dimension of the cyst we decided for surgical excision of the mass. The cyst contained clear and translucent fluid and was successfully removed. Pleuropericardial window was created to prevent pericardial effusion. Histopathological report suggested the diagnosis of bronchogenic cyst because of the presence of smooth muscle. Bronchogenic cyst are closed epithelial-lined sacs developed from the respiratory system as the result of an abnormal budding process during the early development of the foregut. These congenital malformations are usually located in the mediastinum or in the lung parenchyma, but atypical locations such as neck, intramedullary part of the spine, diaphragm or intraabdominal region have been reported. Only a few cases occurring in the heart have been described, but their location in the left ventricle is extremely rare. Bronchogenic cyst are usually asymptomatic: symptoms are related to the interaction with the adjacent structures and therefore depend on the dimensions and the localization of the mass. Surgical approach is mandatory if a complication occurs. Conversely there is not a unique approach for asymptomatic mass as in our case. The young age of the baby and the absence of symptoms argued in favor of a "watchful waiting" strategy. Nevertheless, the particular localization of the cyst at the crux cordis level, its relatively rapid growth and above all the evidence of a close relationship with the coronary arteries, suggesting a concrete risk of compression with further enlargement, were determinant for the final decision for surgical excision. Abstract P268 Figure 1


2021 ◽  
Vol 6 (2) ◽  
pp. 31-36
Author(s):  
M. S. Belimenko ◽  
◽  
V. V. Kosharniy ◽  
L. V. Abdul-Ogly ◽  
G. O. Kozlovskaya

Hypothermia is a situation in which the internal body temperature drops below 35 degrees Celsius. The article presents the relevance, theoretical aspects and features of the action of general hypothermia on the heart in general and cardiomyocytes in particular. The purpose of the study was to study the changes in the myocardium under the action of general hypothermia at different levels of structural organization. The object of the study were the hearts of laboratory adult rats. The study involved 20 animals. The longitudinal section shows that the right ventricle is much thinner than the left and its cavity is presented in the form of a crescent. The interventricular septum is thicker than the wall of the right ventricle and goes into its cavity. Results. To establish the shape of the heart and track the dynamic changes at the organ level, we calculated an index showing the ratio of the width of the heart to its length. In 80% of cases, the heart shape of intact rats was conical, the index averaged 55%, only 20% elliptical, the index was more than 65%. We did not observe other forms of heart in the group of intact rats. In the experimental groups, a spherical heart shape appeared. The thickness of the anterior wall of the left ventricle for 10 days from the beginning of the experiment was 3.15±0.11 mm, the side wall 3.1±0.11 mm, the posterior wall 2.45±0.04 mm, interventricular septum 2.95±0.09 mm. In the right ventricle, the thickness of the anterior wall is 1.04±0.03 mm, the posterior wall is 1.36±0.04 mm. On the 30th day from the beginning of the experiment, the thickness of the anterior wall of the left ventricle was 3.21±0.11 mm, the side wall 2.65±0.06 mm, the posterior wall 3.27±0.09 mm, the interventricular septum 3.14±0.13 mm. In the right ventricle, the thickness of the anterior wall is 1.09±0.04 mm, the posterior wall is 1.38±0.03 mm. Conclusions. The increase in heart mass, change in its shape due to changes in the middle third of the heart wall of both the left and right ventricles. The highest rates were in the middle third of the heart (zone "B"): In all layers of the myocardium there is an increase in the diameter of cardiomyocytes, a decrease in the distance between individual cardiomyocytes and their groups. The distance between adjacent cardiomyocytes in the left ventricle is: in the outer layer 1/8 of the diameter of the cardiomyocyte, between groups of cardiomyocytes 1/4 of the diameter of the cardiomyocyt


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
A. Ratajska ◽  
G. Gula ◽  
A. Flaht-Zabost ◽  
E. Czarnowska ◽  
B. Ciszek ◽  
...  

The role of the cardiac lymphatic system has been recently appreciated since lymphatic disturbances take part in various heart pathologies. This review presents the current knowledge about normal anatomy and structure of lymphatics and their prenatal development for a better understanding of the proper functioning of this system in relation to coronary circulation. Lymphatics of the heart consist of terminal capillaries of various diameters, capillary plexuses that drain continuously subendocardial, myocardial, and subepicardial areas, and draining (collecting) vessels that lead the lymph out of the heart. There are interspecies differences in the distribution of lymphatic capillaries, especially near the valves, as well as differences in the routes and number of draining vessels. In some species, subendocardial areas contain fewer lymphatic capillaries as compared to subepicardial parts of the heart. In all species there is at least one collector vessel draining lymph from the subepicardial plexuses and running along the anterior interventricular septum under the left auricle and further along the pulmonary trunk outside the heart and terminating in the right venous angle. The second collector assumes a different route in various species. In most mammalian species the collectors run along major branches of coronary arteries, have valves and a discontinuous layer of smooth muscle cells.


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