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Rodriguez-Rivera GJ, Post A, John M, Buchan S, Bernard D, Razavi M, Cosgriff-Hernandez E. Injectable hydrogel electrodes as conduction highways to restore native pacing. Nat Commun 2024; 15:64. [PMID: 38167848 PMCID: PMC10762156 DOI: 10.1038/s41467-023-44419-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 12/11/2023] [Indexed: 01/05/2024] Open
Abstract
There is an urgent clinical need for a treatment regimen that addresses the underlying pathophysiology of ventricular arrhythmias, the leading cause of sudden cardiac death. The current report describes the design of an injectable hydrogel electrode and successful deployment in a pig model with access far more refined than any current pacing modalities allow. In addition to successful cardiac capture and pacing, analysis of surface ECG tracings and three-dimensional electroanatomic mapping revealed a QRS morphology comparable to native sinus rhythm, strongly suggesting the hydrogel electrode captures the deep septal bundle branches and Purkinje fibers. In an ablation model, electroanatomic mapping data demonstrated that the activation wavefront from the hydrogel reaches the mid-myocardium and endocardium much earlier than current single-point pacing modalities. Such uniform activation of broad swaths of tissue enables an opportunity to minimize the delayed myocardial conduction of heterogeneous tissue that underpins re-entry. Collectively, these studies demonstrate the feasibility of a new pacing modality that most closely resembles native conduction with the potential to eliminate lethal re-entrant arrhythmias and provide painless defibrillation.
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Affiliation(s)
| | - Allison Post
- Electrophysiology Clinical Research and Innovations, Texas Heart Institute, Houston, TX, 77030, USA
| | - Mathews John
- Electrophysiology Clinical Research and Innovations, Texas Heart Institute, Houston, TX, 77030, USA
| | - Skylar Buchan
- Electrophysiology Clinical Research and Innovations, Texas Heart Institute, Houston, TX, 77030, USA
| | - Drew Bernard
- Electrophysiology Clinical Research and Innovations, Texas Heart Institute, Houston, TX, 77030, USA
| | - Mehdi Razavi
- Electrophysiology Clinical Research and Innovations, Texas Heart Institute, Houston, TX, 77030, USA.
- Division of Cardiology, Department of Medicine, Baylor College of Medicine, Houston, TX, 77030, USA.
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Wright KN, Morley T, Bicknell J, Bishop SP, Walcott GP, Kay GN. Retrograde coronary venous infusion of ethanol for ablation of canine ventricular myocardium. J Cardiovasc Electrophysiol 1998; 9:976-84. [PMID: 9786078 DOI: 10.1111/j.1540-8167.1998.tb00138.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Permanent cure of reentrant ventricular tachycardia (VT) associated with coronary artery disease is difficult to achieve. Retrograde coronary venous infusion of ethanol for ablation of ventricular myocardium associated with reentrant tachyarrhythmias has several potential advantages, including use of physiologic mapping techniques and production of deeper, wider necrotic zones. METHODS AND RESULTS Nine anesthetized dogs had baseline hemodynamic measurement, left ventriculography, coronary arteriography, occlusive coronary venography, and programmed electrical stimulation of the right ventricular apex and outflow tract. A balloon-tipped infusion catheter was advanced into a distal coronary venous branch, the balloon slowly inflated, and pure ethanol infused at volumes of 1.5, 3, or 5 cc. Hemodynamic measurements, angiography, ventriculography, and programmed electrical stimulation were repeated immediately and 1 week following ablation. Formalin-perfused hearts were serially sectioned and lesion volumes determined. Histologic examination of ablation beds then was performed. No significant difference was found in any hemodynamic measurement before or after ablation. Coronary arteriograms and left ventriculograms were unchanged after ablation. Nonsustained VT occurred in eight dogs during ethanol infusion; however, VT was not inducible in any dog before or after ablation. Infusion volumes of 3 cc or more were required to produce transmural lesions. CONCLUSION Retrograde coronary venous infusions of ethanol using a balloon-tipped infusion catheter were effective in ablating ventricular myocardium. Retrograde chemical ablation did not itself result in inducible VT or adversely affect hemodynamic measurements or coronary arteries. Transmural myocardial necrosis, necessary in the ablation of VT associated with coronary artery disease, can be produced by higher infusion volumes.
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Affiliation(s)
- K N Wright
- Division of Cardiovascular Disease, The University of Alabama at Birmingham, USA
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Kar S, Barnett JC, Freedman RJ, Donohue BC, Lasorda D, Jacobs AK. Synchronized coronary venous retroperfusion. J Am Coll Cardiol 1994; 24:579-81. [PMID: 8080543 DOI: 10.1016/0735-1097(94)90322-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Incorvati RL, Tauberg SG, Pecora MJ, Macherey RS, Krucoff MW, Dianzumba SB, Donohue BC. Clinical applications of coronary sinus retroperfusion during high risk percutaneous transluminal coronary angioplasty. J Am Coll Cardiol 1993; 22:127-34. [PMID: 8509532 DOI: 10.1016/0735-1097(93)90826-m] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OBJECTIVES This study was designed to determine the efficacy of synchronized coronary sinus retroperfusion of arterial blood in reducing myocardial ischemia associated with the performance of high risk coronary angioplasty. BACKGROUND Previous animal and clinical work has demonstrated the efficacy of this technique in supporting ischemic myocardium. METHODS Twenty-one patients were randomized to alternately receive coronary sinus retroperfusion support during either the second or the third coronary angioplasty balloon inflation, after an initial unsupported brief control inflation. Myocardial ischemia was assessed by the extent of echocardiographic left ventricular wall motion abnormality, quantified ST segment deviation and hemodynamic and anginal variables during balloon inflations performed with and without coronary sinus retroperfusion support. Regional wall motion score was defined as hyperkinesia (-1), normokinesia (0), hypokinesia (+1), akinesia (+2) and dyskinesia (+3). RESULTS A reduction in the echocardiographic left anterior descending regional wall motion score in retroperfusion-supported (1.7 +/- 2.1) versus unsupported (2.7 +/- 1.6) inflations (p < 0.05) was noted. Twelve-lead electrocardiographic monitoring revealed no additional ST segment deviation during supported (173 +/- 95 s) compared with unsupported (129 +/- 87 s) angioplasty inflations despite a significantly longer duration of supported inflations (p < 0.004). Mean and peak systolic coronary sinus pressures differed during supported inflations (21 +/- 6 and 44 +/- 13 mm Hg) versus unsupported inflations (10 +/- 4 and 16 +/- 5 mm Hg) (p < 0.001). There was no difference in hemodynamic or anginal variables. CONCLUSIONS A reduction in ischemia as defined by wall motion abnormality during retroperfusion-supported compared with unsupported angioplasty balloon inflations was documented. No additional ST segment deviation occurred during retroperfusion-supported compared with unsupported balloon inflations despite a significantly longer duration of supported inflations. No difference in hemodynamic or anginal variables was noted.
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Affiliation(s)
- R L Incorvati
- Department of Medicine, Allegheny General Hospital, Medical College of Pennsylvania, Pittsburgh
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Oh BH, Volpini M, Kambayashi M, Murata K, Rockman HA, Kassab GS, Ross J. Myocardial function and transmural blood flow during coronary venous retroperfusion in pigs. Circulation 1992; 86:1265-79. [PMID: 1394933 DOI: 10.1161/01.cir.86.4.1265] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND The degree of recovery of regional myocardial contraction during coronary venous retroperfusion has not been well established, particularly in the absence of coronary collateral channels. Therefore, the maximal functional benefit attainable with coronary venous retroperfusion was assessed in pigs by means of using selective pump retroperfusion of the left anterior descending vein, with venting of the left anterior descending artery to zero pressure. METHODS AND RESULTS In eight anesthetized open-chest pigs during selective left anterior descending venous retroperfusion over a range of retroperfusion flows, regional myocardial function (percent systolic wall thickening by sonomicrometry) increased progressively to an average of 62% of control values at a retroperfusion flow rate 200% of control arterial flow. Progressive thickening of the end-diastolic dimension of the anterior wall was observed with increasing retroperfusion flow (from 8.7 +/- 0.9 to 10.7 +/- 2.3 mm, p less than 0.001). Perfusion pressures within the left anterior descending vein increased linearly with increased retroperfusion flow rates (up to 132 +/- 57 mm Hg with retroperfusion flow 200% of control). A gradual increase of retrograde left anterior descending arterial outflow was observed with increasing retroperfusion flows; however, the absolute amount (maximum, 8.3 +/- 4.1 ml/min) was much too low to explain the extent of functional recovery. Transmural myocardial capillary blood flows in the anterior wall with retroperfusion flows of 100% and 200% of control arterial flow were 0.22 and 0.42 ml/min/g with corresponding subendocardial blood flows of 0.14 and 0.29 ml/min/g; ratios of endocardium to epicardium were 0.51 and 0.61, respectively. Thus, capillary blood flows during selective retroperfusion were relatively low despite considerable restoration of regional systolic wall thickening, and a significant difference was noted in the slopes of the relations between regional systolic wall thickening and myocardial blood flow during retroperfusion and anterograde arterial perfusion (p less than 0.05). With retrograde injection of silicone elastomer at different retroperfusion pressures (50, 75, and 100 mm Hg) in three pigs, capillaries were well visualized, and profuse intramyocardial venous anastomotic connections were seen at the highest retroperfusion pressure (100 mm Hg), whereas there was filling of small venules but little capillary filling at the lowest retroperfusion pressure (50 mm Hg). CONCLUSIONS Considerable recovery of regional myocardial function with low regional capillary blood flows were observed during acute venous retroperfusion with high retroperfusion flows with arterial blood. These findings together with low levels of retrograde arterial outflow and visualization of retrograde capillary filling with a rich venous network provide evidence for possible oxygen delivery via the intramyocardial venous plexus.
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Affiliation(s)
- B H Oh
- Department of Medicine, University of California San Diego, La Jolla 92093-0613
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Hatori N, Sjöquist PO, Regårdh C, Rydén L. Pharmacokinetic analysis of coronary sinus retroinfusion in pigs. Ischemic myocardial concentrations in the left circumflex coronary arterial area using metoprolol as a tracer. Cardiovasc Drugs Ther 1991; 5:1005-10. [PMID: 1801888 DOI: 10.1007/bf00143528] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Myocardial availability of drug, using metoprolol as a tracer, in acutely ischemic myocardium in the area of the left circumflex (LCX) coronary artery was compared following standard intravenous (IV) administration and after coronary sinus retroinfusion. Seven open-chest farm pigs were subjected to a 21-minute occlusion of the LCX coronary artery. All animals received simultaneous IV tritium-labeled metoprolol (0.2 mg/kg) and unlabeled metoprolol (0.2 mg/kg) retrogradely into the coronary sinus. The drug administration was started after 1 minute of coronary artery occlusion and continued for 5 minutes. Intravenously administered metoprolol resulted in a higher peak plasma concentration of metoprolol (382 +/- 52 nmol/l) than coronary sinus retroinfusion (276 +/- 47 nmol/l). The nonischemic myocardial metoprolol concentration was of similar magnitude (393-454 pmol/g), whether infused IV or into the coronary sinus. Coronary sinus retroinfusion, however, resulted in a substantial accumulation of metoprolol in the ischemic myocardium (2887-5863 pmol/g). Coronary sinus retroinfusion resulted in a pronounced and specific accumulation in the ischemic myocardium in the territory of the LCX coronary artery.
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Affiliation(s)
- N Hatori
- National Defense Medical College, Saitana, Japan
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Miyazaki A, Tadokoro H, Drury JK, Rydén L, Haendchen RV, Corday E. Retrograde coronary venous administration of recombinant tissue-type plasminogen activator: a unique and effective approach to coronary artery thrombolysis. J Am Coll Cardiol 1991; 18:613-20. [PMID: 1906906 DOI: 10.1016/0735-1097(91)90621-f] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Recent studies of interventional therapy by way of the coronary venous system have demonstrated that it can protect acutely ischemic myocardium. To evaluate the efficacy of coronary venous retroinfusion compared with systemic intravenous administration of recombinant tissue-type plasminogen activator (rt-PA), 14 dogs were studied with a copper coil-induced thrombus in the left anterior descending coronary artery. The rt-PA (24,000 fluorescence units/kg) was administered continuously, either intravenously (n = 8) or retrogradely (n = 6), for 30 min beginning 60 min after coronary occlusion. Thrombolysis was determined by repetitive coronary angiography. All dogs were killed 3 h after termination of rt-PA infusion and infarct size was measured by the triphenyltetrazolium chloride staining technique. Complete thrombolysis occurred in five of the six dogs in the retroinfusion group and four of the eight dogs in the systemic intravenous infusion group. Partial lysis was achieved in two dogs treated by intravenous infusion. Lysis did not occur in one dog treated with retroinfusion and in two dogs treated with intravenous infusion. Time to thrombolysis was 13.4 +/- 2.3 min in the retroinfusion group versus 27.8 +/- 4.8 min in the intravenous group (p less than 0.001). Myocardial functional recovery in the ischemic zone measured by two-dimensional echocardiography 60 min after reperfusion was significant only in the retroinfusion group (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- A Miyazaki
- Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California
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O'Byrne GT, Nienaber CA, Miyazaki A, Araujo L, Fishbein MC, Corday E, Schelbert HR. Positron emission tomography demonstrates that coronary sinus retroperfusion can restore regional myocardial perfusion and preserve metabolism. J Am Coll Cardiol 1991; 18:257-70. [PMID: 2050930 DOI: 10.1016/s0735-1097(10)80248-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Positron emission tomography was used to image blood flow and metabolic tracers in risk zone myocardium after left anterior descending coronary artery occlusion during synchronized coronary venous retroperfusion. Six control and seven intervention open chest dogs had occlusion of the mid left anterior descending coronary artery. Synchronized retroperfusion commenced 25 min later. Flow tracers (rubidium-82 and nitrogen-13 ammonia) were injected retrogradely. Three hours after coronary occlusion, fluorine-18 (F-18) deoxyglucose uptake in the control and treatment groups was compared. At 200 min of occlusion, infarct size was assessed. Retrograde flow tracer uptake was observed in the risk zone in the seven intervention dogs. Fluorine-18 deoxyglucose uptake in the risk zone was increased in five of the six intervention dogs but was reduced in five of the six control dogs. The risk zone to normal zone F-18 deoxyglucose count ratio was higher in the intervention than the control group (1.13 +/- 0.39 vs. 0.59 +/- 0.51; p less than 0.05). The endocardial subsegment risk zone to normal zone F-18 deoxyglucose count ratio was also significantly higher in the intervention group. Percent infarction in the risk zone was 70% lower in the group treated with synchronized retroperfusion than in the control group (18.4 +/- 22.6% vs. 61.2 +/- 25.4%; p less than 0.02). Thus, positron emission tomography revealed that retroperfusion could deliver oxygenated blood and maintain metabolism in risk zone myocardium. Infarct size was limited to 30% of that of control. In acute closure of the left anterior descending coronary artery, synchronized retroperfusion might be considered for maintaining viability of the jeopardized myocardium if the artery cannot be reopened rapidly.
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Affiliation(s)
- G T O'Byrne
- Department of Radiological Sciences, University of California, Los Angeles School of Medicine 90024-1721
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Costantini C, Sampaolesi A, Serra CM, Pacheco G, Neuburger J, Conci E, Haendchen RV. Coronary venous retroperfusion support during high risk angioplasty in patients with unstable angina: preliminary experience. J Am Coll Cardiol 1991; 18:283-92. [PMID: 2050932 DOI: 10.1016/s0735-1097(10)80250-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Synchronized coronary venous retroperfusion was used during coronary balloon angioplasty to support the ischemic myocardium of 20 patients with unstable angina and anatomy at high risk of a coronary event. Hemodynamics and left ventricular function were the major end points of the study. Coronary venous catheterization and retroperfusion were successfully performed in 15 patients. The target vessel was an unprotected left main artery in 2, left anterior descending artery in 10, left circumflex coronary artery in 1 and right coronary artery in 2 patients. A nonsupported balloon inflation (mean 44 +/- 13 s) was compared with a later retroperfusion-supported inflation (mean 145 +/- 21 s). Right anterior oblique left ventriculograms, aortic blood pressure, pulmonary artery pressure and thermodilution cardiac output were obtained before and during peak untreated and treated balloon inflations and on completion of angioplasty. All patients had either a baseline left ventricular ejection fraction less than 0.40 or greater than 40% of contracting myocardium estimated to be at risk for severe ischemia during angioplasty. The cardiac (liters/min per m2) and stroke work (g.m/m2) indexes decreased from mean baseline values of 2.5 +/- 0.52 and 52 +/- 15 to 1.7 +/- 0.47 and 27 +/- 12 (mean +/- SD), respectively, during nonsupported balloon inflations but decreased only to 2.1 +/- 0.52 (p less than 0.01 vs. nonsupported) and to 36 +/- 14 (p = 0.01 vs. nonsupported), respectively, during retroperfusion-supported inflations. Ejection fraction (n = 8) decreased from a baseline value of 55 +/- 13% to 27 +/- 7.3% during nonsupported inflations but only to 39 +/- 10% during retroperfusion-supported inflations (p = 0.01 vs. nonsupported). Regional wall motion (area change) in the ischemic (target) region was reduced from a baseline value of 49 +/- 17% to 11 +/- 16% during nonsupported inflations but only to 27 +/- 15% during retroperfusion-supported inflations (p less than 0.01 vs. nonsupported). All but two patients had a favorable hemodynamic response to retroperfusion. There were no serious adverse effects related to the procedures and no hospital deaths. It is concluded from this preliminary study that coronary venous retroperfusion appears to be safe, to provide hemodynamic support and to improve left ventricular function during angioplasty in patients with unstable angina and anatomy at high risk of a coronary event.
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Affiliation(s)
- C Costantini
- Instituto Modelo de Cardiologia, Cordoba, Argentina
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Kar S, Drury JK, Hajduczki I, Eigler N, Wakida Y, Litvack F, Buchbinder N, Marcus H, Nordlander R, Corday E. Synchronized coronary venous retroperfusion for support and salvage of ischemic myocardium during elective and failed angioplasty. J Am Coll Cardiol 1991; 18:271-82. [PMID: 2050931 DOI: 10.1016/s0735-1097(10)80249-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
To determine the safety and efficacy of synchronized coronary venous retroperfusion during brief periods of ischemia, 30 patients undergoing angioplasty of the left anterior descending coronary artery were studied. Each patient underwent a minimum of two angioplasty balloon inflations. Alternate dilations were supported with retroperfusion; the unsupported inflations served as the control inflations. Synchronized retroperfusion was performed by pumping autologous femoral artery blood by means of an electrocardiogram-triggered retroperfusion pump into the great cardiac vein through a triple lumen 8.5F balloon-tipped retroperfusion catheter inserted percutaneously from the right internal jugular vein. Clinical symptoms, hemodynamics and two-dimensional echocardiographic wall motion abnormalities were analyzed. Retroperfusion was associated with a lower angina severity score (0.8 +/- 1 vs. 1.2 +/- 1) and delay in onset of angina (53 +/- 31 vs. 37 +/- 14 s; p less than 0.05) compared with the control inflations. The magnitude of ST segment change was 0.11 +/- 0.14 mV with retroperfusion and 0.16 +/- 0.17 mV without treatment (p less than 0.05). The severity of left ventricular wall motion abnormality was also significantly (p less than 0.01) reduced with retroperfusion compared with control (0.7 +/- 1.4 [hypokinesia] vs. -0.3 +/- 1.6 [dyskinesia]). There were no significant changes in hemodynamics, except in mean coronary venous pressure, which increased from 8 +/- 3 mm Hg at baseline to 13 +/- 6 mm Hg with retroperfusion. Four patients required prolonged retroperfusion for treatment of angioplasty-induced complications. The mean retroperfusion duration in these patients was 4 +/- 2 h (range 2 to 7). In the three patients who underwent emergency bypass surgery, the coronary sinus was directly visualized during surgery and found to be without significant injury. There were no major complications. Minor adverse effects were transient atrial fibrillation (n = 2), jugular venous catheter insertion site hematomas (n = 4) and atrial wall staining (n = 1), all of which subsided spontaneously. Thus, retroperfusion significantly reduced and delayed the onset of coronary angioplasty-induced myocardial ischemia and provided effective supportive therapy for failed and complicated angioplasty.
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Affiliation(s)
- S Kar
- Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California 90048
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Meesmann M, Karagueuzian HS, Ino T, McGrath MF, Mandel WJ. The role of enhanced vagal activity on ischemic ventricular tachycardia: pharmacologic basis of inefficiency. Am Heart J 1991; 121:1703-13. [PMID: 1674635 DOI: 10.1016/0002-8703(91)90016-b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The effects of pharmacologic modulation of vagal activity on ischemic ventricular tachycardia were evaluated in 21 conscious dogs after permanent left anterior descending coronary artery (LAD) occlusion. Studies were done on spontaneous ventricular tachycardia (cycle length 383 +/- 100 msec, n = 21), 24 to 72 hours after LAD occlusion, and on inducible sustained monomorphic ventricular tachycardia (cycle length 251 +/- 30 msec, n = 6), 4 to 7 days after LAD occlusion. Edrophonium (1 mg/kg intravenously), a cholinesterase inhibitor, and methacholine (0.1 to 1 mg intravenously), a muscarinic agonist, had no significant effect on the rate or QRS morphology of either type of tachycardia, despite severe slowing of the sinoatrial rate. Similarly, atropine (up to 60 micrograms/kg intravenously) had no effect on the rate and QRS morphology of either type of tachycardia. In an attempt to enhance myocardial drug delivery to the ischemic and infarcted left ventricle, edrophonium (1 mg/kg) and methacholine (0.1 to 0.2 mg) were injected retrogradely through the great cardiac vein. This did not impart any significant therapeutic advantage over the systemic intravenous route. Sympathetic beta blockade did not affect the therapeutic outcome (n = 5) with either edrophonium or methacholine. It is concluded that direct or indirect enhancement of cardiac vagal activity has no effect on ischemic ventricular tachycardia in this model of subacute myocardial infarction. The lack of efficacy appears to be independent of myocardial drug delivery to ischemic ventricular site(s) and background sympathetic activity. Such a lack of efficacy may be caused by ischemia-mediated degeneration of vagal nerve terminals, by altered responsiveness of muscarinic receptors at infarcted arrhythmogenic myocardial sites, or both.
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Affiliation(s)
- M Meesmann
- Division of Cardiology, Cedars-Sinai Medical Center, Los Angeles, CA 90048
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Wappel M, Zalewski A, Savage M, Hessen S, Goldberg S, Maroko PR. Myocardial salvage after regional beta-adrenergic blockade. Am Heart J 1989; 117:37-42. [PMID: 2911988 DOI: 10.1016/0002-8703(89)90654-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
UNLABELLED The aim of the study was to determine whether regional beta-adrenergic blockade via the coronary sinus limited myocardial damage after coronary artery occlusion in the canine model. Accordingly, open-chest anesthetized dogs were randomly allocated to one of three groups: a control group and groups treated with propranolol (in doses of 0.02, 0.2, and 2.0 mg/kg) given either intravenously or via the coronary sinus. The hypoperfused zone (i.e., risk area) and the extent of myocardial damage were assessed by autoradiography and triphenyltetrazolium chloride staining, respectively. Myocardial damage expressed as a percent of the hypoperfused zone was 84 +/- 5% in the control group (n = 9) and 78 +/- 7% (0.02 mg/kg, n = 7, NS), 63 +/- 6% (0.2 mg/kg, n = 7, p less than 0.05), and 62 +/- 7% (2.0 mg/kg, n = 9, p less than 0.02) in the groups receiving intravenous propranolol and 73 +/- 6% (0.02 mg/kg, n = 7, NS), 58 +/- 7% (0.2 mg/kg, n = 7, p less than 0.01), and 44 +/- 9% (2.0 mg/kg, n = 9, p less than 0.001) in groups receiving propranolol via the cardiac veins. There was a significant enhancement of myocardial salvage with increasing doses of propranolol delivered via the cardiac veins (linear regression trend, p less than 0.05). In contrast, myocardial damage expressed as a percent of the hypoperfused zone remained comparable with propranolol doses of 0.2 and 2.0 mg/kg administered intravenously (linear regression trend, NS). IN CONCLUSION (1) regional beta-adrenergic blockade via the cardiac veins afforded significant myocardial salvage and (2) the regional administration of propranolol resulted in significant reduction of myocardial damage in a dose-dependent fashion.
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Affiliation(s)
- M Wappel
- Department of Medicine, Thomas Jefferson University Hospital, Philadelphia, PA 19107
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Rooke TW, Osmundson PJ. Effect of intermittent venous occlusion on transcutaneous oxygen tension in lower limbs with severe arterial occlusive disease. Int J Cardiol 1988; 21:76-8. [PMID: 3220605 DOI: 10.1016/0167-5273(88)90012-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
We evaluated the ability of intermittent venous occlusion to improve cutaneous circulation in patients with severe peripheral arterial occlusive disease. Fourteen patients with ischemic lower extremities had a pneumatic cuff placed around the thigh of an ischemic limb; intermittent inflation of this cuff produced a significant increase in the transcutaneous oxygen tension of the foot, suggesting that cutaneous blood flow had been improved.
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Affiliation(s)
- T W Rooke
- Mayo Clinic, Mayo Foundation, Division of Cardiovascular Diseases, Rochester, Minnesota 55905
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Torres-Gómez JM. Coronary venous retroperfusion. J Am Coll Cardiol 1988; 11:1138. [PMID: 3356831 DOI: 10.1016/s0735-1097(98)90077-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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