scholarly journals Leadless Pacing with Mechanical Atrial Sensing and Variable AV Conduction

2021 ◽  
Author(s):  
Jason Cook ◽  
Travis Richardson
Keyword(s):  
Av Conduction ◽  
Leadless Pacing ◽  
Atrial Sensing

Development of an Atrioventricular (AV) conduction block in the rat- investigation tool for effects of heart failure

2013 ◽  
Vol 61 (S 01) ◽  
Author(s):  
S Pecha ◽  
F Weinberger ◽  
Y Yildirim ◽  
B Sill ◽  
L Conradi ◽  
...  
Keyword(s):  
Heart Failure ◽  
Conduction Block ◽  
Av Conduction ◽  
Av Conduction Block

Recent Advances in Pacing and Defibrillation

2011 ◽  
Vol 3 (1) ◽  
pp. 74
Author(s):  
Kathy L Lee ◽  
Keyword(s):  
Cardiac Death ◽  
Electronic Devices ◽  
Implantable Defibrillators ◽  
Cardiac Pacemakers ◽  
Cardiac Implantable Electronic Devices ◽  
Treatment And Prevention ◽  
Recent Advances ◽  
Pacing Lead ◽  
Leadless Pacing ◽  
Device Complications

Cardiac pacemakers have been the standard therapy for patients with bradyarrhythmias for several decades. The pacing lead is an integral part of the system, serving as a conduit for the delivery of energy pulses to stimulate the myocardium. However, it is also the Achilles’ heel of pacemakers, being the direct cause of most device complications both acutely during implant and chronically years afterwards. Leadless pacing with ultrasound-mediated energy has been demonstrated in animals and humans to be safe and feasible in acute studies. Implantable defibrillators revolutionised the treatment and prevention of sudden cardiac death. Subcutaneous implantable defibrillators have been under development for more than 10 years. A permanent implantable system has been shown to be feasible in treating induced and spontaneous ventricular tachyarrhythmias. These developments and recent advances in pacing and defibrillation will arouse further interest in the research and development of leadless cardiac implantable electronic devices.

scholarly journals Complete heart block in cardiac sarcoidosis reversed by corticosteroid therapy: time course of resolution

2021 ◽  
Vol 14 (3) ◽  
pp. e240834
Author(s):  
Anna Tomdio ◽  
Huzaefah Syed ◽  
Kenneth Ellenbogen ◽  
Jordana Kron
Keyword(s):  
Heart Block ◽  
Time Course ◽  
Cardiac Sarcoidosis ◽  
Complete Heart Block ◽  
Positron Emission ◽  
Av Conduction ◽  
Magnetic Resonance Imaging Mri ◽  
High Level ◽  
Active Inflammation ◽  
Lateral Walls

A 53-year-old man was admitted for recurrent syncope and found to have complete heart block (CHB). Cardiac magnetic resonance imaging MRI) showed extensive patchy late gadolinium enhancement in the apical and lateral walls, consistent with cardiac sarcoidosis (CS) but no scar in the septum. A fluorodeoxyglucose (FDG)–positron emission tomography showed FDG uptake in the septum and basal lateral walls. Imaging suggested active inflammation in the septum affecting atrioventricular (AV) conduction but no irreversible fibrosis. Diagnosis of isolated CS requires a high level of suspicion and multidisciplinary teamwork involving heart failure specialists, electrophysiologists and rheumatologists. After specialist and patient discussion, treatment of the disease was initiated with prednisone 40 mg daily, 11 months after presenting with CHB. Three weeks later, ECG with pacing inhibited showed second-degree AV block Mobitz type II and 4 weeks later, AV conduction recovery. This highlights the importance of immediate therapy in reversing AV conduction abnormalities in CS.

Atrial Rate Adaptive Pacing: What Happens to AV Conduction?

1994 ◽  
Vol 17 (10) ◽  
pp. 1581-1589 ◽  
Author(s):  
CECILIA LINDE ◽  
ROLF NORDLANDER ◽  
MARTEN ROSENQVIST
Keyword(s):  
Atrial Rate ◽  
Av Conduction ◽  
Rate Adaptive

Effects of physiological aging on cardiac electrophysiology in perfused Fischer 344 rat hearts

1992 ◽  
Vol 262 (1) ◽  
pp. H97-H105 ◽  
Author(s):  
O. Schmidlin ◽  
S. Bharati ◽  
M. Lev ◽  
J. B. Schwartz
Keyword(s):  
Heart Rate ◽  
Age Differences ◽  
Cardiac Electrophysiology ◽  
Histopathological Examination ◽  
Conduction Time ◽  
Fischer 344 Rats ◽  
Aging Effects ◽  
Middle Aged ◽  
Fischer 344 ◽  
Av Conduction

Aging effects on heart rate and atrioventricular (AV) conduction were studied in Langendorff-perfused hearts from 18 mature (4-6 mo), 12 middle-aged (12-14 mo), and 18 senescent (24-26 mo) Fischer 344 rats. Heart rate decreased with increasing age from 218 +/- 18 in mature to 196 +/- 27 (mean +/- SD) beats/min in middle-aged rats to 183 +/- 22 beats/min in senescent rats (analysis of variance, P less than 0.001). Spontaneous AV conduction time increased from 43 +/- 7 to 49 +/- 5 to 62 +/- 9 ms with aging (P less than 0.0001). Paced AV conduction time also lengthened with aging, and AV Wenckebach block cycle length increased from 122 +/- 10 to 133 +/- 9 to 152 +/- 16 ms (P less than 0.005). Intra-atrial conduction time was unaffected by age. Age differences in heart rate and AV conduction responses to isoproterenol (0.5 x 10(-9) to 1 x 10(-7) M) were noted with greater sensitivity at lower doses in hearts from younger rats. In separate experiments, 18 mature and 19 senescent Fischer 344 rats received reserpine (0.25 mg.kg-1.day-1 ip) for 6 days before study. Age differences in heart rate and AV conduction persisted (P less than 0.0001). Histopathological examination of AV nodal and His-bundle tissues in three hearts from each age group showed increased intercellular collagen with advancing age.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiorespiratory interactions in patients with atrial flutter

2009 ◽  
Vol 106 (1) ◽  
pp. 29-39 ◽  
Author(s):  
Michela Masè ◽  
Marcello Disertori ◽  
Flavia Ravelli
Keyword(s):  
Atrial Flutter ◽  
Time Delays ◽  
Supraventricular Arrhythmia ◽  
Sinus Arrhythmia ◽  
Respiratory Arrhythmia ◽  
Strongly Coupled ◽  
Av Conduction ◽  
Frequency Independent ◽  
Modulation Pattern ◽  
Short Time

Respiratory sinus arrhythmia (RSA) is generally known as the autonomically mediated modulation of the sinus node pacemaker frequency in synchrony with respiration. Cardiorespiratory interactions have been largely investigated during sinus rhythm, whereas little is known about interactions during reentrant arrhythmias. In this study, cardiorespiratory interactions at the atrial and ventricular level were investigated during atrial flutter (AFL), a supraventricular arrhythmia based on a reentry, by using cross-spectral analysis and computer modeling. The coherence and phase between respiration and atrial (γ[Formula: see text], φAA) and ventricular (γ[Formula: see text], φRR) interval series were estimated in 20 patients with typical AFL (68.0 ± 8.8 yr) and some degree of atrioventricular (AV) conduction block. In all patients, atrial intervals displayed oscillations strongly coupled and in phase with respiration (γ[Formula: see text]= 0.97 ± 0.05, φAA = 0.71 ± 0.31 rad), corresponding to a paradoxical lengthening of intervals during inspiration. The modulation pattern was frequency independent, with in-phase oscillations and short time delays (0.40 ± 0.15 s) for respiratory frequencies in the range 0.1–0.4 Hz. Ventricular patterns were affected by AV conduction type. In patients with fixed AV conduction, ventricular intervals displayed oscillations strongly coupled (γ[Formula: see text]= 0.97 ± 0.03) and in phase with respiration (φRR = 1.08 ± 0.80 rad). Differently, in patients with variable AV conduction, respiratory oscillations were secondary to Wencheback rhythmicity, resulting in a decreased level of coupling (γ[Formula: see text]= 0.50 ± 0.21). Simulations with a simplified model of AV conduction showed ventricular patterns to originate from the combination of a respiratory modulated atrial input with the functional properties of the AV node. The paradoxical frequency-independent modulation pattern of atrial interval, the short time delays, and the complexity of ventricular rhythm characterize respiratory arrhythmia during AFL and distinguish it from normal RSA. These peculiar features can be explained by assuming a direct mechanical action of respiration on AFL reentrant circuit.

Cardiorenal effects of lidocaine and procaine amide in the conscious dog

1975 ◽  
Vol 228 (5) ◽  
pp. 1440-1445 ◽  
Author(s):  
WJ Mandel ◽  
MM Laks ◽  
AI Arieff ◽  
K Obayashi ◽  
H Hayakawa ◽  
...  
Keyword(s):  
Renal Function ◽  
Cardiac Conduction ◽  
Right Atrial ◽  
Acute Administration ◽  
Conduction Time ◽  
Conscious Dog ◽  
Av Conduction ◽  
Renal Flow ◽  
The Right ◽  
Procaine Amide

Simultaneous measurements of hemodynamics, arterioventricular (AV) conduction, and renal functioner were obtained in conscious dogs. Catheters were implanted for the long-term measurement of central aortic, right ventricular, and pulmonary artery pressure. AV conduction was assessed following surgical implantation of multipolar electrode plaques in the area of the bundle of His, as well as on the epicardium of the right and left atria and ventricles. Renal function was assessed utilizing standard techniques. Following control measurements, lidocaine, 1 mg/kg, or procaine amide, 10 mg/kg, was administered intravenously. Subsequently, serial measurements were obtained for a 90-min period. No significant changes in hemodynamics were observed following either drug. Procaine amide produced a significant increase in heart rate and a minimal increase in QRS duration associated with a decrease in low right atrial to His bundle conduction time. However, no significant changes in cardiac conduction were observed after lidocaine administration. Renal function was unaffected by lidocaine but significantly depressed by procaine amide, as demonstrated by a decrease in GFR and effective renal flow. In summary, acute administration of procaine amide significantly alters renal function in the conscious dog with minimal effects on AV conduction and hemodynamics.

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