P6014The variable location of the atrioventricular conduction axis. Implications for permanent and safe His bundle pacing

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
J A Cabrera ◽  
A Porta Sanchez ◽  
J M Rubio ◽  
Y Macias ◽  
O Salvador-Montanes ◽  
...  
Keyword(s):  
Tricuspid Valve ◽  
Fibrous Tissue ◽  
Right Atrial ◽  
His Bundle ◽  
Fibrous Body ◽  
Marked Variability ◽  
Av Conduction ◽  
Dissection Techniques ◽  
Membranous Septum ◽  
Medial Area

Abstract Background/Introduction The deleterious effects of long-term RV apical pacing have been well recognized. Permament His bundle (HB) pacing has emerged as a promising technique for patients who need ventricular pacing. Purpose To describe the anatomy of the HB region and its variations for successfully approaching HB pacing in a safer and more efficient way and to understand selective vs non-selective HB pacing and to avoid permanent damage to it. Methods In 57 structurally normal human heart specimens (48 males, 77±7 years) we examined by dissection techniques and histological sections the course of the penetrating and non-branching His bundle in relation with the membranous septum and the tricuspid valve (TV) annulus. We correlated these anatomic findings with a series of angiographic studies in 60 patients (47% males, 45±16 years old) by recording the largest His electrogram sites within the limits of the triangle of Koch (TK) and the plane of the TV. Results The membranous septum is divided by the attachment on its right side of the septal leaflet of the tricuspid valve into atrioventricular (AV) and interventricular components. The AV component of the membranous septum forms the anterosuperior apex of the TK and showed in cadaveric hearts variable dimensions in length (4.6±1.5 mm, range 1–9 mm). The AV node becomes the His bundle as the AV conduction axis enters the AV component of the membranous septum and is encircled by the fibrous tissue of the central fibrous body in 100% of hearts with none of them having a “naked” entrance to it. In 30 hearts (53%) the HB penetrates the AV membranous septum at the apex of the TK at the hinge point of the septal leaflet of the TV near its commissure with the anterosuperior leaflet. However in 47% of cases the HB crossed the fibrous tissue of the central fibrous body in a lower position in the medial area of the paraseptal right atrial region of the TK with a mean distance to the AV membranous septum of 4±1.4 mm (range 1.5–8 mm) above and behind the TV annulus. These findings correlate with those obtained in patients in which the site of recording of the largest His bundle deflection does not always coincide with the anterosuperior vertex of the triangle as judged angiographically. In 51% of patients the site of the largest His bundle electrograms was found in the medial area of the triangle above (posterior-inferior) the TV annulus while in 49% of patients the His was recorded at the same level (15%) or below (anterior-inferior) the TV annulus (34% of patients) (figure). Histology of HB and catheter locations Conclusions Knowledge of the marked variability in the location of the AV conduction bundle within the paraseptal right atrial region is crucial for approaching permanent HB pacing. An anterior-inferior and ventricular HB location could yield to restriction of the septal leaflet of the tricuspid valve if a lead is to be deployed in the area.

P6015Histological pattern of penetrating His bundle division: implications for atrioventricular conduction damage during and following transcatheter aortic valve implantation

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
J A Cabrera ◽  
A Porta-Sanchez ◽  
D Nunez Pernas ◽  
J M Rubio ◽  
F Navarro ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Ventricular Outflow Tract ◽  
Left Ventricular ◽  
His Bundle ◽  
Transcatheter Aortic Valve ◽  
Av Conduction ◽  
Left Ventricular Outflow ◽  
The Right ◽  
Valve Implantation ◽  
Membranous Septum

Abstract Background Severe damage to the atrioventricular conduction system is one of the most common complications of transcatheter aortic valve implantation (TAVI) and can be linked to important comorbidity, increased healthcare expense, need for long-term monitoring and pacemaker implantation. Purpose To provide a detailed description of the His bundle (HB) arrangement within the left ventricular outflow tract. Methods We examined by dissection techniques and histological sections the course of the AV conduction axis (penetrating, non-branching and branching HB) in relation with the membranous and muscular interventricular septum in 57 structurally normal human heart specimens (48 males, 77±7 years) Results The AV conduction axis is located along the inferior edge of the membranous septum (MS). The MS is divided into AV and interventricular components and is located at the base of the interleaflet triangle between the right and non-coronary leaflets of the aortic valve. The conduction axis enters the AV component of the MS and is encircled by the fibrous tissue of the central fibrous body to reach the left ventricular outflow tract. The MS showed in cadaveric hearts variable dimensions in length (4.6±1.5 mm) with a range bewteen 1 to 9mm. In 17.5% of specimens the MS length was ≤2 mm. After penetrating the AV membranous septum it has a non-branching component that in 85.5% of cases runs only for a short distance (1–3 mm) along the septal crest before giving rise to the fascicles of the left bundle (LB) on the septal surface (Type A). The most anterior fibers of the LB originate at the end of the branching portion located underneath the inferior edge of the MS. In 5 hearts (9%) the HB division was found before it reached the interventricular MS (Type B) and in 3 cases (5.5%)2–3.5 mm distal to the crest (Type C). 22 hearts (49%) were shown to have a relatively left-sided deviation of the AV bundle with the anterior part of the bundle closely related to the nadir of attachment of the right coronary leaflet of the aortic valve. In the remaining 51% of hearts, the bundle coursed centrally or with a right-sided deviation. The HB measures were (mm, mean±SD (range)): length: 3±0.6 (2–4.5), width: 3.7±1.4 (2.5–5.6), thickness: 1.4±0.5 (0.5–2.2), HB to endocardium: 0.7±0.3 (0.2–1.5). His bundle position types Conclusions A shorter membranous septum length, the variable HB dimensions and the left-sided deviation of the AV conduction axis are extremely relevant anatomic features that are linked to the frequent injury to the HB branch or complete AV block following TAVI.

The Gerbode Defect: The Significance of a Left Ventricular to Right Atrial Shunt

2009 ◽  
Vol 19 (S2) ◽  
pp. 96-99 ◽  
Author(s):  
Angela M. Kelle ◽  
Luciana Young ◽  
Sunjay Kaushal ◽  
C. Elise Duffy ◽  
Robert H. Anderson ◽  
...  
Keyword(s):  
Ventricular Septal Defect ◽  
Tricuspid Valve ◽  
Right Atrium ◽  
Septal Defect ◽  
Left Ventricular ◽  
Right Atrial ◽  
Surgical Closure ◽  
The Mean ◽  
The Right ◽  
Membranous Septum

AbstractBackgroundThe so-called Gerbode ventriculo-atrial defect is a rare defect that permits shunting from the left ventricle to the right atrium. It takes 2 forms, either a deficiency of the atrioventricular membranous septum, or shunting initially through a ventricular septal defect, with atrial shunting occurring through a deficiency in the septal leaflet of the tricuspid valve. In this review, we describe the natural history and outcomes of surgical repair for the variant with shunting through a deficiency at the site of the atrioventricular membranous septum.MethodsFrom 1990 to 2008, we identified 6 patients from our departmental database who had undergone surgical closure of a congenital defect of the atrioventricular component of the membranous septum. Median age at repair was 1.6 years, with a range, from 0.4 to 19 years. All patients were symptomatic, with 3 having congestive cardiac failure, 2 failing to thrive, and 2 having intolerance to exercise. All had a dilated right atrium demonstrated by echocardiogram, with a mean preoperative gradient measured by echocardiogram to be 109 millimetres of mercury, with a range from 65 to 150 millimetres of mercury.ResultsThere was no operative or late mortality. The mean size of the defect was 6.2 ± 2.0 millimetres, with a range from 4 to 8 millimetres. All were closed by insertion of a patch. The mean period of cardiopulmonary bypass was 90.5 ± 11.3 minutes, the mean time of aortic cross-clamping 54.8 ± 6.9 minutes, and the mean length of stay in hospital 4.3 ± 1.0 days. No patient had a residual defect, and only trivial regurgitation of the tricuspid valve was evident by postoperative echocardiography. There were no complications or reoperations.ConclusionThe membranous ventriculo-atrial defect can be recognized echocardiographically on the basis of dilation of the right atrium in the setting of an unusually high Doppler echocardiogram gradient compared to the ventricular septal defect with shunting only at ventricular level. Since all patients in our series were symptomatic, we recommend surgical closure of all these defects.

Physiological Pacing: A New Road to Future

2021 ◽  
pp. 263246362097804
Author(s):  
Vanita Arora ◽  
Pawan Suri
Keyword(s):  
Side Effects ◽  
Fibrous Tissue ◽  
Cardiac Pacing ◽  
His Bundle ◽  
Anatomy And Physiology ◽  
Long Term Follow Up ◽  
Pacing Lead ◽  
The Right

Anatomy and physiology are the basis of human body functioning and as we have progressed in management of various diseases, we have understood that physiological intervention is always better than an anatomical one. For more than 50 years, a standard approach to permanent cardiac pacing has been an anatomical placement of transvenous pacing lead at the right ventricular apex with a proven benefit of restoring the rhythm. However, the resultant ventricular dyssynchrony on the long-term follow-up in patients requiring more than 40% ventricular pacing led to untoward side effects in the form of heart failure and arrhythmias. To counter such adverse side effects, a need for physiological cardiac pacing wherein the electrical impulse be transmitted directly through the normal conduction system was sought. His bundle pacing (HBP) with an intriguing alternative of left bundle branch pacing (LBBP) is aimed at restoring such physiological activation of ventricles. HBP is safe, efficacious, and feasible; however, localization and placement of a pacing lead at the His bundle is challenging with existing transvenous systems due to its small anatomic size, surrounding fibrous tissue, long-learning curve, and the concern remains about lead dislodgement and progressive electrical block distal to the HBP lead. In this article, we aim to take the reader through the challenging journey of HBP with focus upon the hardware and technique, selective versus nonselective HBP, indications and potential disadvantages, and finally the future prospects.

scholarly journals RIGHT ATRIAL DYSFUNCTION IN FETUSES WITH SEVERE TRICUSPID VALVE DISEASE: NOVEL EXPERIENCE WITH VELOCITY VECTOR IMAGING

2010 ◽  
Vol 55 (10) ◽  
pp. A44.E419 ◽  
Author(s):  
Lisa W. Howley ◽  
Nee Szce Khoo ◽  
Anita Moon-Grady ◽  
Fayeza Alrais ◽  
Jean Trines ◽  
...  
Keyword(s):  
Tricuspid Valve ◽  
Velocity Vector ◽  
Valve Disease ◽  
Right Atrial ◽  
Velocity Vector Imaging

scholarly journals Asymptomatic right atrial leiomyosarcoma with tricuspid valve obstruction in a young female patient

1998 ◽  
Vol 14 (6) ◽  
pp. 635-638 ◽  
Author(s):  
A. Kornberg ◽  
S.M. Wildhirt ◽  
E. Kreuzer ◽  
B. Reichart
Keyword(s):  
Female Patient ◽  
Tricuspid Valve ◽  
Young Female ◽  
Right Atrial

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.

scholarly journals Tricuspid Valve Dysplasia in a Dog

2019 ◽  
Vol 47 ◽  
Author(s):  
Gabriela De Carvalho Cid ◽  
Luciano Da Silva Alonso ◽  
Ana Paula De Castro Pires ◽  
Mariana Siqueira d'Avila Taïna Gonçalves ◽  
Taïna Gonçalves ◽  
...  
Keyword(s):  
Right Ventricular ◽  
Tricuspid Valve ◽  
Right Atrial ◽  
Pulmonary Insufficiency ◽  
Papillary Muscles ◽  
Ventricular Enlargement ◽  
Pathological Findings ◽  
Chordae Tendineae ◽  
Clinicopathological Findings ◽  
The Right

Background: Congenital cardiac diseases are a common cause of death in puppies. Tricuspid valve dysplasia is characterized by thickening and displacement of the leaflets of the tricuspid valve, agenesis of the valves, and incomplete separation of valve components. Papillary muscles may fuse and display shortened or absent chordae tendineae that contribute to tricuspid regurgitation. Diagnostic features of tricuspid valve dysplasia include cardiomegaly with massive right atrium enlargement on thoracic radiography and tricuspid insufficiency on an ultrasound. We aimed to describe clinicopathological findings in a dog (Canis familiaris) with tricuspid dysplasia.Case: We aimed to describe tricuspid valve dysplasia in a dog referred for necropsy at the Anatomical Pathology Sector of The Rural Federal University of Rio de Janeiro, Brazil, with a clinical history of abdominal swelling, dyspnea, cyanosis, ascites, and prostration. Echocardiography and abdominal ultrasound revealed right ventricular enlargement, hepatomegaly, and splenomegaly. Examination of the heart showed prominent enlargement, thickening and dilation of the right chambers, thickening of the tricuspid leaflets, and moderately shortened chordae tendineae. The liver was enlarged, with a nutmeg pattern, and foci of clotting and fibrin adhesions in the lateral right lobule.Discussion: Epidemiological, clinical, and pathological findings were consistent with tricuspid valve dysplasia. Although structural abnormalities of the tricuspid and mitral valves are well known in fetuses and neonates, congenital and secondary tricuspid malformations are rare in dogs. The survival rate is associated with the severity of heart lesions. Tricuspid valve dysplasia is mostly observed in large-breed dogs (>20 kg), particularly in Labrador Retrievers, Boxers, and German Shepherds. Regardless, most dogs with tricuspid valve dysplasia are of a pure-breed, which differs from our findings because our dog was a mongrel. Our dog displayed signs of dyspnea, cyanosis, abdominal swelling, prostration, and enlarged liver and spleen on ultrasound examination. Tricuspid valve dysplasia led to heart enlargement and right congestive heart failure, with consequent ascites, abdominal swelling, weakness, lethargy, jugular venous distension, and hepatomegaly. Overall, the heart showed prominent enlargement, thickening and dilation of the right chambers, thickening of the tricuspid leaflets, and moderately shortened chordae tendineae. The liver had a nutmeg pattern. Tricuspid valve dysplasia is characterized by malformation of the tricuspid valve leaflets, chord tendineae, or papillary muscles. Malformed tricuspid valves are known to result in variable degrees of regurgitation, leading to right atrial overflow and ventricular eccentric hypertrophy. Differential diagnosis includes myocarditis, tricuspid valve endocarditis, tricuspid endocardiosis, tricuspid valve prolapse and right ventricular dysplasia, right ventricular enlargement with tricuspidal regurgitation due to pulmonary insufficiency, and arrhythmogenic right ventricular cardiomyopathy. Signs of heart murmurs (irregular sounds of the heart) on clinical examination may indicate an irregular blood flow pattern, and imaging tests may be necessary for assessing the presence and severity of any lesions. The epidemiologic, clinical, and pathological findings were consistent with those of tricuspid valve dysplasia. 

CONGENITAL HEART BLOCK DUE TO A LESION IN THE CONDUCTION SYSTEM

PEDIATRICS ◽  
1970 ◽  
Vol 45 (4) ◽  
pp. 640-650
Author(s):  
Cirilo Sotelo-Avila ◽  
Harvey S. Rosenberg ◽  
Dan G. McNamara
Keyword(s):  
Heart Block ◽  
Congenital Heart ◽  
Complete Heart Block ◽  
Fibrous Tissue ◽  
Postmortem Examination ◽  
Conduction System ◽  
Cardiac Conduction ◽  
Fibrous Body ◽  
Congenital Complete Heart Block ◽  
Bundle Of His

The cardiac conduction system of an infant with congenital complete heart block was studied at postmortem examination by subserial sections of the interatrial and interventricular septa. A localized area of necrosis in the central fibrous body interrupted the penetrating portion of the bundle of His. The cardiac structure was intact, with no abnormality other than the lesions in the fibrous tissue. The lesion is interpreted as the result of an acquired inflammation late in intrauterine life, with damage localized to the cardiac central fibrous body.

Inotropic, chronotropic, and dromotropic effects mediated via parasympathetic ganglia in the dog heart

2000 ◽  
Vol 279 (3) ◽  
pp. H1201-H1207 ◽  
Author(s):  
Masato Tsuboi ◽  
Yasuyuki Furukawa ◽  
Koichi Nakajima ◽  
Fumio Kurogouchi ◽  
Shigetoshi Chiba
Keyword(s):  
Superior Vena ◽  
Vena Cava ◽  
Contractile Force ◽  
Right Atrial ◽  
Fat Pad ◽  
Parasympathetic Ganglia ◽  
Dog Heart ◽  
Parasympathetic Nerves ◽  
Av Conduction ◽  
Stimulation Of

Some parasympathetic ganglionic cells are located in the epicardial fat pad between the medial superior vena cava and the aortic root (SVC-Ao fat pad) of the dog. We investigated whether the ganglionic cells in the SVC-Ao fat pad control the right atrial contractile force, sinus cycle length (SCL), and atrioventricular (AV) conduction in the autonomically decentralized heart of the anesthetized dog. Stimulation of both sides of the cervical vagal complexes (CVS) decreased right atrial contractile force, increased SCL, and prolonged AV interval. Stimulation of the rate-related parasympathetic nerves to the sinoatrial (SA) node (SAPS) increased SCL and decreased atrial contractile force. Stimulation of the AV conduction-related parasympathetic nerves to the AV node prolonged AV interval. Trimethaphan, a ganglionic nicotinic receptor blocker, injected into the SVC-Ao fat pad attenuated the negative inotropic, chronotropic, and dromotropic responses to CVS by 33∼37%. On the other hand, lidocaine, a sodium channel blocker, injected into the SVC-Ao fat pad almost totally inhibited the inotropic and chronotropic responses to CVS and partly inhibited the dromotropic one. Lidocaine or trimethaphan injected into the SAPS locus abolished the inotropic responses to SAPS, but it partly attenuated those to CVS, although these treatments abolished the chronotropic responses to SAPS or CVS. These results suggest that parasympathetic ganglionic cells in the SVC-Ao fat pad, differing from those in SA and AV fat pads, nonselectively control the atrial contractile force, SCL, and AV conduction partially in the dog heart.

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