Electrophysiological Basis for Supraventricular Arrhythmias

Bush, Harry L.; Gelband, Henry; Hoffman, Brian F.; Malm, James R.

doi:10.1001/archsurg.1971.01350110122020

Cited by 17 publications

(4 citation statements)

References 35 publications

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“…These unplanned surgeries included revision of shunt type after stage I operation and ligation of veno-venous collaterals after stage II. These patients had in common some combination of progressive cyanosis, chamber dilatation, and increased wall stress, all of which could have contributed to arrhythmia susceptibility 11, 12 .…”

Section: Discussionmentioning

confidence: 99%

Arrhythmias in patients with hypoplastic left heart syndrome

Trivedi

Smith

Barker

et al. 2011

American Heart Journal

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Background Mortality between stage I and II palliation for hypoplastic left heart syndrome (HLHS) has been associated with arrhythmias. The stage-related proportion, associations, and clinical impact of arrhythmias in patients with HLHS have not been evaluated. Also, arrhythmia subtypes have not been described in this patient group. Methods We performed a retrospective analysis of all patients at Duke University Medical Center who received one or more palliative stages for hypoplastic left heart syndrome from September 2000 to October 2008. Results Overall, 49/86 (57%) patients had 63 arrhythmias. The majority of arrhythmias occurred between stage I and II with 44/86 (51%) patients manifesting a new arrhythmia. Arrhythmias occurring in this interval tended to be associated with a higher mortality compared to arrhythmias occurring after stage II, OR = 3.2 [95%CI 0.84, 12.0] (p=0.09). Overall, mortality was similar in patients with and without arrhythmias (p=0.99). Supraventricular tachycardia was the most common arrhythmia (16/63; 25%) but persistent bradycardias (sinus node dysfunction or high grade atrioventricular block) had the worst clinical outcome with 73% mortality (8/11). There was no association between arrhythmia occurrence and degree of tricuspid regurgitation, left ventricular hypertension, genetic syndrome, type of stage I operation, or need for extracorporeal membrane oxygenation (ECMO). Conclusions A large proportion of patients with HLHS experience serious arrhythmias requiring therapy, especially between stages I and II. Persistent bradycardia following stage I is associated with a high mortality rate. Considering all arrhythmia patients, overall mortality was not different compared to the arrhythmia free group.

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Section: Discussionmentioning

confidence: 99%

Arrhythmias in patients with hypoplastic left heart syndrome

Trivedi

Smith

Barker

et al. 2011

American Heart Journal

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“…Half‐activation voltage was approximately ‐86 mV, which does not support a functional role for this current under physiological conditions in human atrial myocytes. In fact, the maximum diastolic potential in human atrial myocytes has been shown to be generally below this value (i.e., ‐70/‐75 mV) (Bush et al , 1971; Gelband et al , 1972; Ten Eick & Singer, 1979; Escande et al , 1985; Singer, 1990; Wang et al , 1993) implying that the current undergoes little, if any, activation. However, the presence of I f in such a high percentage of atrial myocytes deserves further investigation.…”

Section: Discussionmentioning

confidence: 99%

“…Normally polarized human atrial specimens may exhibit a diastolic depolarization phase (Bush et al , 1971; Escande et al , 1986; Singer, 1990), which has been implicated in initiating atrial arrhythmias (Bush et al , 1971). Consequently, we thought that it would be important to have more information on the characteristics of I f in human atrial myocytes, on its incidence, i.e.…”

Section: Introductionmentioning

confidence: 99%

The pacemaker current I_f in single human atrial myocytes and the effect of β‐adrenoceptor and A₁‐adenosine receptor stimulation

Porciatti

Pelzmann

Cerbai

et al. 1997

British J Pharmacology

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1 We used single human atrial myocytes to study I f occurrence, properties and pharmacological modulation. Cells were obtained by chunk enzymatic digestion from samples of right atrial appendages of patients undergoing corrective cardiac surgery. 2 Patch-clamped cells in the whole-cell con®guration were superfused with a modi®ed Tyrode solution to reduce contamination by interfering currents and to amplify I f . The average cell membrane capacitance was 85.06+2.41 pF (n=531). Data were consistent with the geometrical dimensions of the cells (length 94.2+1.89 mm, width 17.9+0.42 mm, n=126). 3 When hyperpolarizing to 7120 mV from a holding potential of 740 mV, 252 of 306 tested cells (82%) expressed a hyperpolarization-activated inward current (I f density =3.77+0.25 pA pF 71 ); the current was considered to be present in a given cell if its density at 7120 mV was larger than 0.5 pA pF 71 . 4 Current activation was sigmoidal and ®tted a Boltzmann model; the average activation curve (n=25) showed a maximum current amplitude of 205.97+19.94 pA, corresponding to 3.87+0.63 pA pF 71 , voltage of half-maximal activation (V 1/2 ) at 786.68+2.19 mV and a slope of 711.39+0.69 mV. The reversal potential of I f measured by tail-current analysis was 713.07+1.92 mV (n=6). The addition of CsCl (5 mM) fully and reversibly blocked the current. 5 In the presence of the b-adrenoceptor agonist isoprenaline (Iso, 1 mM), V 1/2 was signi®cantly shifted toward less negative potentials by 6.06+1.96 mV (n=16, P=0.0039). The selective A 1 -adenosine receptor agonist cyclopentyladenosine (CPA, 1 mM) caused a statistically signi®cant shift of V 1/2 toward more negative potentials with respect to the control curve, both in the absence (77.37+1.83 mV, P=0.0005, n=11) and in the presence of 1 mM Iso (74.97+1.78, P=0.031, n=6). 6 These results demonstrate that a current with the properties of I f described in cardiac primary and secondary pacemakers occurs in the majority of human atrial cells. While the pathophysiological relevance of I f in human atrial tissue remains to be de®ned, our data clearly show that it is modulated through stimulation of b-adrenoceptors and A 1 -adenosine receptors.

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“…RA hemodynamics were normal according to pre-operative clinical assessment and studies have previously shown that RA myocardial cells of young patients with aortic stenosis have normal electrophysiological characteristics [13]. Approval for examination of surgical tissue was obtained prior to operation.…”

Section: Methodsmentioning

confidence: 99%

Atrial Remodeling After the Fontan Operation

Wolf

Seslar

Boer

et al. 2009

The American Journal of Cardiology

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Hemodynamics following Fontan surgery are notable for right atrial (RA) hypertension and dilation. The effect of this stress on atrial cytoarchitecture has not been studied systematically, and may be relevant to arrhythmias and their treatment. Morphologic and histopathologic analysis was performed on RA and left atrial (LA) tissue from post-mortem specimens of Fontan hearts (n = 47) and compared to control samples from young patients with normal atrial hemodynamics (n = 15). Most Fontan specimens were from young patients who expired after a relatively short duration of Fontan physiology. Tissues were analyzed for wall thickness, fibrosis content, and fibrosis pattern. Mean wall thickness for both RA (3.0±1.0 mm) and LA (2.3±0.6 mm) in Fontan hearts was significantly greater than in control hearts (RA = 1.8±0.4 mm and LA = 1.8±0.5 mm, p<0.001 and p=0.024, respectively). Predictors for RA thickening included: a) older age at Fontan surgery, b) older age at death, and c) longer duration of Fontan circulation. Fontan hearts and controls exhibited nearly identical RA and LA fibrosis patterns. Neither wall thickness nor fibrosis varied with underlying heart defect or style of Fontan connection. In conclusion, atrial remodeling after Fontan surgery for univentricular heart physiology involves increased wall thickness in both the RA and LA. Interstitial fibrosis was also observed in Fontan atria, but because a similar pattern was present in control tissue, this likely represents normal fibroelastic atrial structure rather than a specific response to Fontan hemodynamics. The degree of wall thickening observed in Fontan atria was not so excessive as to preclude transmural lesions during catheter or surgical ablation of reentrant arrhythmias.

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Electrophysiological Basis for Supraventricular Arrhythmias

Cited by 17 publications

References 35 publications

Arrhythmias in patients with hypoplastic left heart syndrome

Arrhythmias in patients with hypoplastic left heart syndrome

The pacemaker current I_f in single human atrial myocytes and the effect of β‐adrenoceptor and A₁‐adenosine receptor stimulation

Atrial Remodeling After the Fontan Operation

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Electrophysiological Basis for Supraventricular Arrhythmias

Cited by 17 publications

References 35 publications

Arrhythmias in patients with hypoplastic left heart syndrome

Arrhythmias in patients with hypoplastic left heart syndrome

The pacemaker current If in single human atrial myocytes and the effect of β‐adrenoceptor and A1‐adenosine receptor stimulation

Atrial Remodeling After the Fontan Operation

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The pacemaker current I_f in single human atrial myocytes and the effect of β‐adrenoceptor and A₁‐adenosine receptor stimulation