Electrophysiologic Effects of Selective Right versus Left Atrial Linear Lesions in a Canine Model of Chronic Atrial Fibrillation

Roithinger, Franz Xaver; Steiner, P.; Goseki, Yoshinari; Sparks, Paul B.; Lesh, Michael D.

doi:10.1111/j.1540-8167.1999.tb00220.x

Cited by 42 publications

(24 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Most importantly, LA ablation increased the cycle length on the RA, whereas RA ablation had no appreciable effect on LA AF cycle length, supporting our idea 6 -8 that the LA is the primary driver during AF, at least in some cases. Our results, together with those of Roithinger et al, 28 open potentially exciting new possibilities for targeting LA sources for therapies, whether ablative, electrical, pharmacological, or hybrid.…”

Section: Discussionsupporting

confidence: 70%

“…Other studies demonstrated a greater rate of success of LA radiofrequency (RF) ablation (60% to 80%) 12,26,27 than of RA ablation to eliminate AF. In a recent study by Roithinger et al, 28 single RA and LA RF ablation caused prolongation of AF cycle length in the ablated atrium. Most importantly, LA ablation increased the cycle length on the RA, whereas RA ablation had no appreciable effect on LA AF cycle length, supporting our idea 6 -8 that the LA is the primary driver during AF, at least in some cases.…”

Section: Discussionmentioning

confidence: 91%

See 1 more Smart Citation

Left-to-Right Gradient of Atrial Frequencies During Acute Atrial Fibrillation in the Isolated Sheep Heart

et al. 2001

View full text Add to dashboard Cite

show abstract

Section: Discussionsupporting

confidence: 70%

Section: Discussionmentioning

confidence: 91%

Left-to-Right Gradient of Atrial Frequencies During Acute Atrial Fibrillation in the Isolated Sheep Heart

et al. 2001

View full text Add to dashboard Cite

show abstract

“…Other studies 27,28 have attached particular importance to the left atrium in the initiation and maintaining of AF and the present study showed that there were aging-associated changes of the electrophysiological properties of the atrial myocardium. In the aged group there was a shorter MAPD90 and ERP of the left atrial myocardium, the shortening ability of the MAPD90 in relation to an increase in the simulation frequency was not maintained in the left atrial myocardium, there were differences between the left and right atrial myocardium, and so on, which we consider would provide the substrate for AF.…”

Section: Discussionsupporting

confidence: 67%

“…Previous studies have also shown that there are differences between the right and left atria in refractoriness and APD, [11][12][13][14][15] which may be an important physiological factor in the maintenance of AF, and the effect of aging on these differences also needs to be further studied.…”

mentioning

confidence: 99%

Differences in the Aging-Associated Trends of the Monophasic Action Potential Duration and Effective Refractory Period of the Right and Left Atria of the Rat

Huang

Ding

et al. 2006

Circ J

View full text Add to dashboard Cite

SolutionsThe pH of Krebs-Henseleit solution [(mmol/L): NaCl 140, KCl 5.4, MgCl2·5H2O 1.0, CaCl2·2H2O 1.8, glucose 5.0, sodium pyruvate 4.0, tris base 10] was adjusted to 7.4 with HCl, and maintained by equilibration with 5%CO2-95%O2. All reagents were of analytical purity grade. Background The incidence of atrial fibrillation (AF) increases with aging, but the aging-associated electrophysiological changes of atrial myocardium are poorly understood. Methods and ResultsBased on the hypothesis that aging of the atrium enhances AF susceptibility, 30 Wistar rats were divided into 3 age groups: adult, middle-aged, and aged (n=20 per group). Their hearts were isolated and perfused by Langendorff apparatus. Monophasic action potential duration at 90% repolarization (MAPD90) and effective refractory period (ERP) at the basic stimulation cycle length (BCL: 400 ms), and MAPD90 at other different stimulation cycle lengths in each age group were measured. At the BCL, the MAPD90 of the right atrial myocardium was prolonged from the adult to the aged group, that of the left atrial myocardium was prolonged from the adult to middle-aged group, and the MAPD90 of the left atrial myocardium in the aged group were shorter than that in the adult and middle-aged groups. The ERP of the atrial myocardium showed the same ageassociated trend as MAPD90. As the stimulation frequency increased, the MAPD90 of both the left and right atrial myocardium shortened correspondingly in the adult and middle-aged groups, but in the aged group the MAPD90 of the right atrial myocardium shortened markedly more than that of the left atrial myocardium. Conclusions There are different aging-associated electrophysiological changes in the right and left atrium, and the older heart is more vulnerable to developing the substrate for AF. (Circ J 2006; 70: 352 -357)

show abstract

“…Whole cell voltage-clamp studies in canine atrial cardiomyocytes showed that atrial tachycardia leads to a substantial reduction in I Ca-L density (24), and 60% reduction of I Ca-L in AF was reported in human atrial cardiomyocytes (38). There is also growing focus on the importance of electrophysiological heterogeneity between both atria in the initiation and maintenance of AF (11,18,21,32). In this study, we show that there are no significant differences in the protein level of the ␣ 1D Ca channel from the left and right atria, suggesting minor contribution of ␣ 1D I Ca-L in the interatrial ionic current heterogeneity.…”

Section: Discussionmentioning

confidence: 55%

Localization and modulation of α_1D (Cav1.3) L-type Ca channel by protein kinase A

Qu¹,

Baroudi²,

Yue³

et al. 2005

American Journal of Physiology-Heart and Circulatory Physiology

View full text Add to dashboard Cite

Ca channel was assumed to be of neuroendocrine origin only; however, ␣ 1D L-type Ca channel knockout mice exhibit sinus bradycardia and atrioventricular block, indicating a distinct role of ␣ 1D in the heart. The presence and distribution of ␣ 1D Ca channel in the heart and its regulation by protein kinase A (PKA) are just emerging. Our objective was to examine the localization of ␣ 1D L-type Ca channel in rabbit and rat hearts and its modulation by PKA. Here, we show the exclusive presence of ␣ 1D Ca channel transcript in the sinoatrial node, atrioventricular node, and atria but not in the ventricle by RT-PCR and the expression of ␣ 1D Ca channel protein in atrial myocytes' sarcolemma by indirect immunostaining and Western blot. There is no significant difference in the expression level of ␣ 1D Ca channel in the left versus right atrium. Superfusion of membrane-permeable 8-bromo-cAMP resulted in a significant increase of the peak current density of ␣ 1D Ca current expressed in tsA201 cells. This increase was inhibited by the PKA inhibitor (PKI). Application of 8-bromo-cAMP also readily phosphorylated the ␣ 1D Ca channel protein. The results are first to demonstrate that PKA phosphorylation of L-type Ca channel ␣ 1D-subunit resulted in an increase of the ␣ 1D Ca channel activity. Together with the observation that ␣ 1D Ca channel is exclusively present in the sinoatrial node and atria, the findings suggest that ␣ 1D Ca channel plays a unique role in the sinoatrial tissue and is a target for sympathetic control of heart rhythm. phosphorylation; protein kinase A; sinoatrial node IN THE CARDIOVASCULAR SYSTEM, voltage-gated L-type Ca channels are essential for the generation of normal cardiac rhythm, for the induction of rhythm propagation through the atrioventricular (AV) node, and for the contraction of the atrial and ventricular muscle (31). Cardiac L-type Ca channels are heterologomeric complexes of up to four subunits: ␣ 1 -, ␤-, and ␣ 2 /␦ subunits. The ␣ 1 -subunit contains the voltage sensor, the selectivity filter, the ion-conducting pore, and the binding sites for all known Ca channel blockers. Four genes encode L-type Ca channel ␣ 1 -subunits in mammals (alpha S, C, D, and F) (7). Alpha S (␣ 1S ) and alpha F (␣ 1F ) expression is restricted to skeletal muscle and the retina. Alpha C (␣ 1C ) represents the most abundant isoform in the cardiovascular system, whereas alpha D (␣ 1D ) is mainly expressed in neurons and neuroendocrine cells.It has therefore long been assumed that the contribution of L-type Ca current (I Ca-L ) to physiology and/or pathophysiology of the heart and the therapeutic effects of Ca channel blockers are mainly mediated through ␣ 1C Ca channel. This assumption has been challenged by recent reports indicating a role of ␣ 1D Ca channel in the pacemaker activity of the sinoatrial (SA) node. Takimoto et al. (37) reported that ␣ 1D Ca channel mRNA is expressed in the rat atrium but not in the ventricles. This is subsequently confirmed by Mangoni et al. (19) who reported a similar observati...

show abstract

Electrophysiologic Effects of Selective Right versus Left Atrial Linear Lesions in a Canine Model of Chronic Atrial Fibrillation

Cited by 42 publications

References 21 publications

Left-to-Right Gradient of Atrial Frequencies During Acute Atrial Fibrillation in the Isolated Sheep Heart

Left-to-Right Gradient of Atrial Frequencies During Acute Atrial Fibrillation in the Isolated Sheep Heart

Differences in the Aging-Associated Trends of the Monophasic Action Potential Duration and Effective Refractory Period of the Right and Left Atria of the Rat

Localization and modulation of α_1D (Cav1.3) L-type Ca channel by protein kinase A

Contact Info

Product

Resources

About

Electrophysiologic Effects of Selective Right versus Left Atrial Linear Lesions in a Canine Model of Chronic Atrial Fibrillation

Cited by 42 publications

References 21 publications

Left-to-Right Gradient of Atrial Frequencies During Acute Atrial Fibrillation in the Isolated Sheep Heart

Left-to-Right Gradient of Atrial Frequencies During Acute Atrial Fibrillation in the Isolated Sheep Heart

Differences in the Aging-Associated Trends of the Monophasic Action Potential Duration and Effective Refractory Period of the Right and Left Atria of the Rat

Localization and modulation of α1D (Cav1.3) L-type Ca channel by protein kinase A

Contact Info

Product

Resources

About

Localization and modulation of α_1D (Cav1.3) L-type Ca channel by protein kinase A