geoscience.net logo
+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Mitral annular dynamics during rapid atrial pacing


, : Mitral annular dynamics during rapid atrial pacing. Surgery 128(2): 361-367

Ovine mitral annular area (MAA) reduction predominantly occurs before ventricular systole. We used the myocardial marker methods to investigate left atrial and MAA dynamics during rapid atrial pacing. Seven sheep underwent implantation of 21 myocardial markers around the mitral annulus, the left ventricle and left atrium. After 7 to 10 days, animals were studied with biplane videofluoroscopy to determine 3-dimensional marker coordinates unpaced and during rapid atrial pacing at 140 minutes(-1). Left ventricle volume, left atrial volume (LAV), and MAA were calculated from marker coordinates. End diastole (ED) was defined at peak of the electrocardiogram R wave; times of minimum MAA and minimum LAV were expressed relative to ED (t = 0). Percent reduction in MAA and LAV were calculated from maximum and minimum values between diastole and early systole. The time of minimum MAA occurred earlier relative to ED during rapid pacing compared with control (-48 +/- 21 vs 19 +/- 14 msec; P <.001), as did the time of minimum LAV (-47 +/- 18 vs 4 +/- 16 msec; P <.001). Minimum MAA and LAV were significantly smaller with rapid pacing (6. 8 +/- 0.6 vs 6.5 +/- 0.5 cm(2); P <.05, respectively; and 15.4 +/- 2. 4 vs 16.5 +/- 2.3 mL; P <.01, respectively), and a relatively greater fractional reduction in MAA and LAV was observed during presystole. Rapid atrial pacing resulted in greater MAA and LAV reduction, both of which occurred entirely during diastole. This study supports the notion that MAA reduction is closely linked to LA dynamics.

US$19.90

PMID: 10923017

DOI: 10.1067/msy.2000.108058


Other references

Smith, Andrew, B.T., 2006: An overview of the classification and evolution of the major scarab beetle clades (Coleoptera : Scarabaeoidea) based on preliminary molecular analyses. We present a preliminary overview of our molecular phylogenetics research on the superfamily Scarabaeoidea. The molecular data consists of 28S ribosomal DNA sequences (mainly D2 and D3 expansion regions) for over 600 taxa and 18S ribosomal DNA se...

Piñeiro Corrales, G.; Olivera Fernández, R.; Guindel Jiménez, C., 2007: Drug administration in patients with enteral tube nutrition. Nutricion Hospitalaria 21 Suppl 4: 1-216

Mitrokhina, M.V., 1982: Potentials of self-examination in detecting ovarian tumors. The clinical picture and primary diagnosis of 739 benign, 114 border-case and 115 early-stage malignant ovarian tumors are discussed. It was established that 8.4-11% of patients had detected tumors themselves by palpation. The detection of tumors...

Zamboanga, B.L.; Schwartz, S.J.; Jarvis, L.Hernandez.; Van Tyne, K., 2009: Acculturation and substance use among Hispanic early adolescents: investigating the mediating roles of acculturative stress and self-esteem. We examined the extent to which Hispanic orientation and American orientation are associated with substance use (cigarette, alcohol, and marijuana) both directly and indirectly through acculturative stress and self-esteem. Participants were 347 Hi...

Gandon, J.; Gehanno, P., 1970: Epitheliomatous degeneration of cysts of the thyroglossal tractus. Annales D'oto-Laryngologie et de Chirurgie Cervico Faciale 87(6): 353-355

Anonymous, 2013: Analysis of combining ability, heterosis effect and heritability estimate of yield-related characters in shallot alium cepa var ascalonicum baker. Low productivity of shallot in Indonesia can be improved through development of high yielding variety. The availability of genetic information related to the character being improved is inevitable for effective breeding program. In this study, sev...

Ntarlagiannis, D.; Ferguson, A., 2009: SIP response of artificial biofilms. In recent years, research into the use of geophysical methods for monitoring microbial activity within the subsurface has advanced. One of the most promising methods, induced polarization (IP), has indirectly shown sensitivity to changes in the pr...

Sottiurai, V.S.; Batson, R.C., 1983: Role of myofibroblasts in pseudointima formation. Twenty Dacron grafts (10 crimped and 10 noncrimped) were studied with light microscopy, scanning electron microscopy, and transmission electron microscopy (TEM) 1 to 10 months after insertion into the canine thoracoabdominal aorta. Fibroblast-deri...

Solomon A.; Frangione B.; Franklin E.C., 1982: Preferential association of the v lambdavi subgroup of human light chains with amyloidosis. Clinical Research 30(2): 515A

Harada, H.; Sugita, Y.; Hayashi, I.; Izumaru, S.; Morimatsu, M., 2000: Small cell carcinoma of the parotid gland Report of two cases. Journal of Oral Pathology & Medicine 29(7): 348, August