scholarly journals Myosin types and fiber types in cardiac muscle. II. Atrial myocardium.

1982 ◽  
Vol 95 (3) ◽  
pp. 838-845 ◽  
Author(s):  
L Gorza ◽  
S Sartore ◽  
S Schiaffino

Antibodies were produced against myosins isolated from the left atrial myocardium (anti-bAm) and the left ventricular myocardium (anti-bVm) of the bovine heart. Cross-reactive antibodies were removed by cross-absorption. Absorbed anti-bAm and anti-bVm were specific for the myosin heavy chains when tested by enzyme immunoassay combined with SDS gel electrophoresis. Indirect immunofluorescence was used to determine the reactivity of atrial muscle fibers to the two antibodies. Three populations of atrial muscle fibers were distinguished in the bovine heart: (a) fibers reactive with anti-bAm and unreactive with anti-bVm, like most fibers in the left atrium; (b) fibers reactive with both antibodies, especially numerous in the right atrium; (c) fibers reactive with anti-bVm and unreactive with anti-bAm, present only in the interatrial septum and in specific regions of the right atrium, such as the crista terminalis. These findings can be accounted for by postulating the existence of two distinct types of atrial myosin heavy chains, one of which is antigenically related to ventricular myosin. The tendency for fibers labeled by anti-bVm to occur frequently in bundles and their preferential distribution in the crista terminalis, namely along one of the main conduction pathways between the sinus node and the atrioventricular node, and in the interatrial septum, where different internodal tracts are known to converge, suggests that these fibers may be specialized for faster conduction.

2005 ◽  
Vol 8 (2) ◽  
pp. 96 ◽  
Author(s):  
Osman Tansel Dar�in ◽  
Alper Sami Kunt ◽  
Mehmet Halit Andac

Background: Although various synthetic materials and pericardium have been used for atrial septal defect (ASD) closure, investigators are continuing to search for an ideal material for this procedure. We report and evaluate a case in which autologous right atrial wall tissue was used for ASD closure. Case: In this case, we closed a secundum ASD of a 22-year-old woman who also had right atrial enlargement due to the defect. After establishing standard bicaval cannulation and total cardiopulmonary bypass, we opened the right atrium with an oblique incision in a superior position to a standard incision. After examining the secundum ASD, we created a flap on the inferior rim of the atrial wall. A stay suture was stitched between the tip of the flap and the superior rim of the defect, and suturing was continued in a clockwise direction thereafter. Considering the size and shape of the defect, we incised the inferior attachment of the flap, and suturing was completed. Remnants of the flap on the inferior rim were resected, and the right atrium was closed in a similar fashion. Results: During an echocardiographic examination, neither a residual shunt nor perigraft thrombosis was seen on the interatrial septum. The patient was discharged with complete recovery. Conclusion: Autologous right atrial patch is an ideal material for ASD closure, especially in patients having a large right atrium. A complete coaptation was achieved because of the muscular nature of the right atrial tissue and its thickness, which is a closer match to the atrial septum than other materials.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Yan Le Ho ◽  
Pui Fong Ng ◽  
Sotheenathan Krishinan ◽  
Basheer Ahamed Abdul Kareem

Abstract Background Papillary fibroelastomas are rare but benign cardiac tumour that are often found on cardiac valvular surfaces. Their clinical manifestations ranging from clinically asymptomatic to substantial complications that are usually secondary to systemic embolism. Multiple theories have been proposed to explain the pathophysiology of its formation. Case presentation We reported a rare case of large papillary fibroelastoma in the right atrium of a young gentleman which was complicated with pulmonary embolism. Transthoracic echocardiography identified a large pedunculated mass measuring 3.4cmX3.4cmX2cm in right atrium with stalk attached to interatrial septum. The intracardiac mass was resected surgically, which revealed papillary fibroelastoma in histology examination. Conclusion Differential diagnosis of intracardiac masses requires clinical information, laboratory tests and imaging modalities including echocardiography. Incidentally discovered papillary fibroelastomas are treated on the basis of their sizes, site, mobility and potential embolic complications. Due to the embolic risk inherent to intraacardiac masses, surgical resection represents an effective curative protocol in treating both symptomatic and asymptomatic right sided and left sided papillary fibroelastomas, with excellent long term postoperative prognosis.


1985 ◽  
Vol 260 (27) ◽  
pp. 14403-14405 ◽  
Author(s):  
P J Reiser ◽  
R L Moss ◽  
G G Giulian ◽  
M L Greaser

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Atsushi Morishita ◽  
Ikuo Hagino ◽  
Hideyuki Tomioka ◽  
Seiichiro Katahira ◽  
Takeshi Hoshino ◽  
...  

Abstract Background Partial anomalous pulmonary venous connection draining into the right atrium with an intact atrial septum is a very rare clinical entity in the adult population. Partial anomalous pulmonary venous connection must be suspected as a differential diagnosis when the cause of right heart enlargement and pulmonary artery hypertension is unknown. Case presentation This study describes the surgical case of an isolated right partial anomalous pulmonary venous connection to the right atrium in a 68-year-old woman, who underwent tricuspid ring annuloplasty and right-sided maze procedure simultaneously. She had complaints of gradually progressing dyspnea on exertion. However, a diagnosis could not be established despite consultations at multiple hospitals for over a year. Right heart catheterization revealed severe pulmonary artery hypertension with a mean pulmonary artery pressure of 46 mmHg, step-up phenomenon of oxygen saturation at the mid-level of the right atrium with a pulmonary-to-systemic blood flow ratio of 2.4, and a pulmonary vascular resistance of 3.1 Wood Units. As medical treatment with pulmonary artery vasodilator therapy did not improve her symptoms, she underwent surgical repair. An atrial septal defect was created surgically with a curvilinear tongue-shaped cut. The right anomalous pulmonary veins were rerouted through the surgically created atrial septal defect into the left atrium with a baffle comprised of the interatrial septum flap, kept in continuity with the anterior margin and sutured while mobilizing the enlarged right atrium. The patient had an uneventful postoperative course and remains asymptomatic. Conclusions The described surgical technique could be considered an effective alternative for patients undergoing surgical repair for a partial anomalous pulmonary venous connection isolated to the right atrium. The indication for surgery must be judged on a case-by-case basis in these patients with prevalent systemic-to-pulmonary shunting.


2001 ◽  
Vol 90 (5) ◽  
pp. 1927-1935 ◽  
Author(s):  
Boris A. Tikunov ◽  
H. Lee Sweeney ◽  
Lawrence C. Rome

To better understand the molecular basis of the large variation in mechanical properties of different fiber types, there has been an intense effort to relate the mechanical and energetic properties measured in skinned single fibers to those of their constituent cross bridges. There is a significant technical obstacle, however, in estimating the number of cross bridges in a single fiber. In this study, we have developed a procedure for extraction and quantification of myosin heavy chains (MHCs) that permits the routine and direct measurement of the myosin content in single muscle fibers. To validate this method, we also compared MHC concentration measured in single fibers with the MHC concentration in whole fast-twitch (psoas and gracilis) and slow-twitch (soleus) muscles of rabbit. We found that the MHC concentration in intact psoas (184 μM) was larger than that in soleus (144 μM), as would be expected from their differing mitochondrial content and volume of myofibrils. We obtained excellent agreement between MHC concentration measured at the single fiber level with that measured at the whole muscle level. This not only verifies the efficacy of our procedure but also shows that the difference in concentration at the whole muscle level simply reflects the concentration differences in the constituent fiber types. This new procedure should be of considerable help in future attempts to determine kinetic differences in cross bridges from different fiber types.


2020 ◽  
Author(s):  
Atsushi Morishtia ◽  
Ikuo Hagino ◽  
Hideyuki Tomioka ◽  
Seiichiro Katahira ◽  
Takeshi Hoshino ◽  
...  

Abstract Background: Partial anomalous pulmonary venous connection draining into the right atrium with an intact atrial septum is a very rare clinical entity in the adult population. Partial anomalous pulmonary venous connection must be suspected as a differential diagnosis when the cause of right heart enlargement and pulmonary artery hypertension is unknown.Case presentation: This study describes the surgical case of an isolated right partial anomalous pulmonary venous connection to the right atrium in a 68-year-old woman, who underwent tricuspid ring annuloplasty and right-sided maze procedure simultaneously. She had complaints of gradually progressing dyspnea on exertion. However, a diagnosis could not be established despite consultations at multiple hospitals for over a year. Right heart catheterization revealed severe pulmonary artery hypertension with a mean pulmonary artery pressure of 46 mmHg, step-up phenomenon of oxygen saturation at the mid-level of the right atrium with a pulmonary-to-systemic blood flow ratio of 2.4, and a pulmonary vascular resistance of 3.1 Wood Units. In addition, it was mandatory to comprehensively utilize valuable imaging modalities, such as transthoracic echocardiography, transesophageal echocardiography, and multidetector computed tomography angiography for the accurate diagnosis and efficient surgical planning of this partial anomalous pulmonary venous connection. As medical treatment with pulmonary artery vasodilator therapy did not improve her symptoms, she underwent surgical repair. An atrial septal defect was created surgically with a curvilinear tongue-shaped cut. The right anomalous pulmonary veins were rerouted through the surgically created atrial septal defect into the left atrium with a baffle comprised of the interatrial septum flap, kept in continuity with the anterior margin and sutured while mobilizing the enlarged right atrium. The patient had an uneventful postoperative course and remains asymptomatic. Conclusions: The described surgical technique could be considered an effective alternative for patients undergoing surgical repair for a partial anomalous pulmonary venous connection isolated to the right atrium. The indication for surgery must be judged on a case-by-case basis in these patients with prevalent systemic-to-pulmonary shunting.


2020 ◽  
Author(s):  
Atsushi Morishita ◽  
Ikuo Hagino ◽  
Hideyuki Tomioka ◽  
Seiichiro Katahira ◽  
Takeshi Hoshino ◽  
...  

Abstract Background: Partial anomalous pulmonary venous connection draining into the right atrium with an intact atrial septum is a very rare clinical entity in the adult population. Partial anomalous pulmonary venous connection must be suspected as a differential diagnosis when the cause of right heart enlargement and pulmonary artery hypertension is unknown.Case presentation: This study describes the surgical case of an isolated right partial anomalous pulmonary venous connection to the right atrium in a 68-year-old woman, who underwent tricuspid ring annuloplasty and right-sided maze procedure simultaneously. She had complaints of gradually progressing dyspnea on exertion. However, a diagnosis could not be established despite consultations at multiple hospitals for over a year. Right heart catheterization revealed severe pulmonary artery hypertension with a mean pulmonary artery pressure of 46 mmHg, step-up phenomenon of oxygen saturation at the mid-level of the right atrium with a pulmonary-to-systemic blood flow ratio of 2.4, and a pulmonary vascular resistance of 3.1 Wood Units. As medical treatment with pulmonary artery vasodilator therapy did not improve her symptoms, she underwent surgical repair. An atrial septal defect was created surgically with a curvilinear tongue-shaped cut. The right anomalous pulmonary veins were rerouted through the surgically created atrial septal defect into the left atrium with a baffle comprised of the interatrial septum flap, kept in continuity with the anterior margin and sutured while mobilizing the enlarged right atrium. The patient had an uneventful postoperative course and remains asymptomatic.Conclusions: The described surgical technique could be considered an effective alternative for patients undergoing surgical repair for a partial anomalous pulmonary venous connection isolated to the right atrium. The indication for surgery must be judged on a case-by-case basis in these patients with prevalent systemic-to-pulmonary shunting.


ISRN Anatomy ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
Abu Ubaida Siddiqui ◽  
Syed Rehan Hafiz Daimi ◽  
Kusum Rajendra Gandhi ◽  
Abu Talha Siddiqui ◽  
Soumitra Trivedi ◽  
...  

Background. The complex architecture of the right atrium, crista terminalis (CT), and the musculi pectinati (MP) poses enormous challenges in electrophysiology and cardiac conduction. Few studies have been undertaken to substantiate the gross features of MP, in relation to the CT, but there is still scarcity of data regarding this. We tried to reinvestigate the gross arrangement of muscle bundles in the right atrium. Methods. Utilizing 151 human hearts and orientation of MP and its variations and relationship to the CT were investigated along with taenia sagittalis (TS). Patterns of MP were grouped in 6 categories and TS under three groups. Result. A plethora of variations were observed. Analysis of all the specimen revealed that 68 samples (45%) were of type 1 category and 27 (18%) fell into type 2 category. Prominent muscular columns were reported in 12 samples (8%). 83 samples (55%) presented with a single trunk of TS. Multiple trunks of TS were reported in 38 samples (25%). Conclusion. Samples with type 6 MP and type B/type C TS, which have a more complex arrangement of fibers, have a tendency to be damaged during cardiac catheterization. Nonetheless, the area as a whole is extremely significant considering the pragmatic application during various cardiac interventions.


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