Pacemaker syndrome

ESC CardioMed ◽  
2018 ◽  
pp. 2011-2016
Author(s):  
Giuseppe Boriani ◽  
Igor Diemberger

Pacemaker syndrome (PMS) is a constellation of symptoms and signs provoked by haemodynamic and biohumoural modifications secondary to ‘any modification of the temporal sequence of atrial and ventricular contraction’ induced by artificial pacing. This clinical entity was early described after the development of artificial pacing but it still lacks a definite characterization. In particular, several mechanisms may induce PMS beyond ventriculoatrial retrograde conduction in a patient with single-chamber pacing, with the interplay of patient characteristics, device hardware/programming, and pharmacological therapy. The contemporary concept of PMS is strictly connected with the idea of ‘physiological pacing’ for which PMS represent the negative extreme. Moreover, any improvement in cardiac pacing provides additional data on PMS such as atrioventricular timing, intraventricular dyssynchrony, and heart rate adaptation.

Mathematics ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 1205
Author(s):  
Timur Gamilov ◽  
Philipp Kopylov ◽  
Maria Serova ◽  
Roman Syunyaev ◽  
Andrey Pikunov ◽  
...  

In this work we present a one-dimensional (1D) mathematical model of the coronary circulation and use it to study the effects of arrhythmias on coronary blood flow (CBF). Hydrodynamical models are rarely used to study arrhythmias’ effects on CBF. Our model accounts for action potential duration, which updates the length of systole depending on the heart rate. It also includes dependency of stroke volume on heart rate, which is based on clinical data. We apply the new methodology to the computational evaluation of CBF during interventricular asynchrony due to cardiac pacing and some types of arrhythmias including tachycardia, bradycardia, long QT syndrome and premature ventricular contraction (bigeminy, trigeminy, quadrigeminy). We find that CBF can be significantly affected by arrhythmias. CBF at rest (60 bpm) is 26% lower in LCA and 22% lower in RCA for long QT syndrome. During bigeminy, trigeminy and quadrigeminy, respectively, CBF decreases by 28%, 19% and 14% with respect to a healthy case.


2021 ◽  
Author(s):  
Daria Aleksandrovna Ponomartseva ◽  
Ilia Vladislavovich Derevitskii ◽  
Sergey Valerevich Kovalchuk ◽  
Alina Yurevna Babenko

Abstract Background: Thyrotoxic atrial fibrillation (TAF) is a recognized significant complication of hyperthyroidism. Early identification of the individuals predisposed to TAF would improve thyrotoxic patients’ management. However, to our knowledge, an instrument that establishes an individual risk of the condition is unavailable. Therefore, the aim of this study is to build a TAF prediction model and rank TAF predictors in order of importance. Methods: In this retrospective study, we have investigated 36 demographic and clinical features for 420 patients with overt hyperthyroidism, 30% of which had TAF. At first, the association of these features with TAF was evaluated by classical statistical methods. Then, we developed several TAF prediction models with eight different machine learning classifiers and compared them by performance metrics. The models included ten features that were selected based on their clinical effectuality and importance for model output. Finally, we ranked TAF predictors, elicited from the optimal final model, by the machine learning tehniques. Results: The best performance metrics prediction model was built with the extreme gradient boosting classifier. It had the reasonable accuracy of 84% and AUROC of 0.89 on the test set. The model confirmed such well-known TAF risk factors as age, sex, hyperthyroidism duration, heart rate and some concomitant cardiovascular diseases (arterial hypertension and conjestive heart rate). We also identified premature atrial contraction and premature ventricular contraction as new TAF predictors. The top five TAF predictors, elicited from the model, included (in order of importance) PAC, PVC, hyperthyroidism duration, heart rate during hyperthyroidism and age. Conclusions: We developed a machine learning model for TAF prediction. It seems to be the first available analytical tool for TAF risk assessment. In addition, we defined five most important TAF predictors, including premature atrial contraction and premature ventricular contraction as the new ones. These results have contributed to TAF prediction investigation and may serve as a basis for further research focused on TAF prediction improvement and facilitation of thyrotoxic patients’ management.


Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Charles H Tegeler ◽  
Catherine L Tegeler ◽  
Hossam A Shaltout

Background: Stress cardiomyopathy or Takotsubo syndrome (TS) is an acute, reversible disorder of the heart characterized by left ventricular dysfunction, usually triggered by a stressful event. Excessive sympathetic excitation and shift in symapthovagal balance are proposed as mechanisms. High-resolution, relational, resonance-based, electroencephalic mirroring (HIRREM®) is a noninvasive, closed-loop, allostatic, neurotechnology using software algorithms to identify specific brain frequencies, translating them in real time into audible tones, to support self-optimization of brain rhythms and improve autonomic balance. Objective: To evaluate benefits of HIRREM on autonomic function and symptom reduction in a 55 year old female enrolled in an IRB-approved open label feasibility study, after TS diagnosis. Results: The participant received 13 HIRREM sessions over 11 days (9 in office days). Data were collected before, and 21 days after HIRREM completion. Baseline brain patterns had prominent right dominance at temporal lobes (sympathetic pattern), which balanced by the end of the sessions. Cardiovascular autonomic balance also shifted away from sympathetic towards parasympathetic. This was seen as reduced LF/HF ratio (from 1.89 to 0.63), increased heart rate variability (rMSSD from 27 to 40.8 ms), and baroreflex sensitivity (from 11.8 to 24.4 ms/mmHg). Blood pressure dropped from 132/90 to 121/88 with no change in heart rate despite discontinuation of her ACE inhibitor medication due to her BP being “too low.” HIRREM use was also associated with clinically meaningful improvements in multiple symptom inventories including insomnia (ISI) from 15 to 6, depression (CES-D) from 16 to 2, anxiety (GAD-7) from 18 to 2, and perceived stress scale (PSS) from 30 to 14. The patient reported resolution of a feeling of heaviness and discomfort in the chest after starting HIRREM sessions. Conclusion: These data provide the first report of potential cardiovascular benefits of a non- pharmacological therapy to patients suffering from broken heart syndrome.


1983 ◽  
Vol 61 (3) ◽  
pp. 229-236 ◽  
Author(s):  
Diane Godin ◽  
Claude Guimond ◽  
Réginald Nadeau

Chemical sympathectomy and bilateral vagotomy were used to evaluate the contribution of each division of the autonomic nervous system in the electrophysiological actions of ouabain. Intact and chemically sympathectomized dogs were given successive and cumulative doses of ouabain until toxicity became manifest (ventricular extrasystoles and (or) ventricular tachycardia). An additional group of normal and sympathectomized animals was also submitted to bilateral vagotomy in the presence of a therapeutic dose of ouabain. Sinus cycle length, AH interval of the His bundle electrogram, atrioventricular junctional effective and functional refractory periods were increased by ouabain at therapeutic doses. These effects were no different in sympathectomized dogs than in intact dogs, indicating the absence of any significant contribution of efferent sympathetic neural activity. However, our results suggested that vagal enhancement was the main mechanism whereby ouabain produced sinus bradycardia and depression of atrioventricular conduction. Sympathectomy with 6-OHDA did not modify nor abolish ouabain toxicity. However, toxic doses were significantly higher in sympathectomized animals than in normal animals. Considering that increasing heart rate by cardiac pacing or vagotomy significantly lowered toxic doses of ouabain in both intact and sympathectomized dogs, it is possible that sympathectomy could influence ouabain toxicity by altering heart rate alone.


1990 ◽  
Vol 4 (3) ◽  
pp. 95-100
Author(s):  
Haruhiko Adachi ◽  
Hiroki Sugihara ◽  
Hiroaki Nakagawa ◽  
Suetsugu Inagaki ◽  
Yasushi Kubota ◽  
...  

1984 ◽  
Vol 54 (1) ◽  
pp. 103-108 ◽  
Author(s):  
Jonnalagedda S.M. Sarma ◽  
Radha J. Sarma ◽  
Michael Bilitch ◽  
Darryl Katz ◽  
Susan L. Song

Heart Rhythm ◽  
2007 ◽  
Vol 4 (3) ◽  
pp. 284-289 ◽  
Author(s):  
Nathan M. Segerson ◽  
Stephen L. Wasmund ◽  
Moeen Abedin ◽  
Rakesh K. Pai ◽  
Marcos Daccarett ◽  
...  

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