Administration Of Cardioplegic Solution Research Articles

Custodiol Histidine-Tryptophan-ketoglutarate Versus Blood Cardioplegia in Totally Thoracoscopic Cardiac Surgery

Objective: The present study aimed to evaluate and compare the myocardial protection performance between Custodial histidine-tryptophan-ketoglutarate cardioplegic solution and blood cardioplegic solution in the context of totally thoracoscopic cardiac surgery. Methods: A total of 101 patients who underwent thoracoscopic cardiac surgery adopting either blood cardioplegic or histidine-tryptophan-ketoglutarate solution at Guangdong Provincial People’s Hospital from January 2021 to December 2021 were retrospectively enrolled. Postoperative outcomes assessed by myocardial enzyme level, the capacity of return to spontaneous rhythm, left ventricle ejection fraction, myocardial infarction, vasoactive-inotropic score, mechanical ventilation time, intensive care unit stay, hospital stay, mechanical circulatory support, and in-hospital mortality were compared between the two groups. Results: 69 and 32 patients adopted blood cardioplegic and histidine-tryptophan-ketoglutarate solutions, respectively. The cardiac troponin I and creatine kinase-MB at the peak period or at the postoperative period of <24h, 24-48h, and >48h were similar between the two groups (p>0.05). There was also no significance regarding the postoperative left ventricle ejection fraction, vasoactive-inotropic score, and incidence of myocardial infarction (p>0.05). However, blood cardioplegic solution administration resulted in a significantly more occurrence of return to spontaneous rhythm in contrast to the histidine-tryptophan-ketoglutarate solution (p=0.025). Multivariate logistic regression for outcomes revealed that histidine-tryptophan-ketoglutarate administration was associated with a lower possibility to return to spontaneous rhythm (odds ratio (OR)=0.238; confidence interval CI=0.072-0.783; p=0.018]. Additionally, increased aortic cross-clamp time per 10 mins was associated with a higher risk of myocardial infarction (OR=1.499; CI=1.161-1.934; p=0.002) while increased total volume was associated with a lower risk of myocardial infarction (OR=0.997; CI=0.994-0.999; p=0.029) Conclusion: Delivery of histidine-tryptophan-ketoglutarate solution offered equivalent myocardial protection to the delivery of blood cardioplegic solution in patients undergoing totally thoracoscopic cardiac surgery. In this setting, the histidine-tryptophan-ketoglutarate seems to be associated with decreased incidence of postoperative return to spontaneous rhythm.

Comparative Analysis of the Effectiveness of Different Options for the Administration of Cardioplegic Solution during Surgical Correction of an Aortic Aneurysm Combined with Coronary Artery Lesions

The aim. To determine the effectiveness of myocardial protection in various variants of administration of cardioplegic solution in patients with aortic aneurysms combined with coronary artery lesions.
 Materials and methods. We analyzed 111 operations for aortic aneurysms combined with lesions of the coronary arteries, which were performed from 2011 to 2020 at the National Amosov Institute of Cardiovascular Surgery of the National Academy of Medical Sciences of Ukraine. The subjects were divided into four groups: group 1 where all three methods of cardioplegic solution administration (antegradely, retrogradely and into alloshunts) were used (60 [54.1%] patients), group 2 with administration of cardioplegic solution retrogradely and into alloshunts (48 [43.2%] patients), group 3 with antegrade and retrograde administration (2 [1.8%] patients), and group 4 with only retrograde administration of cardioplegic solution (1 [0.9%] patient). Of these operations, 19 (17.1%) were performed for acute type A aortic dissection, 4 (53.6%) for chronic type A aortic dissection, 88 (79.3%) for aortic aneurysm without dissection. The most common surgical interventions performed were: Robicsek procedure (41 [36.9%] interventions), Bentall – de Bono procedure (40 [36.0%] interventions), supracoronary ascending aortic replacement (22 [19.8%] operations), Wheat procedure (7 [6.3%] interventions).
 Results. According to our results, the aortic cross-clamp time was longer in group 2 (p < 0.05). The average time of extubation in groups 1 and 2 did not differ significantly (p > 0.05). At the same time, the average time of stay of patients in the intensive care unit differed significantly (p < 0.05) in patients of groups 1 (168.92 ± 121.54 h) and 2 (199.35 ± 214.42 h), which indicates faster recovery of patients of group 1. We diagnosed a total of 34 (30.6%) complications in 111 operated patients. A significant number of complications, namely 20 (33.3%) cases, were observed in group 1. The most frequent complications in this group were atrial fibrillation which occurred in 4 (6.7%) cases and hemorrhagic complications which were observed in 3 (5.0%) cases; of these, 1 (1.7%) case was with hemothorax and hemopericardium (this patient underwent rethoracotomy), 1 (1.7%) with hemopericardium and tamponade, and 1 (1.7%) with hemothorax. Of the 111 operations analyzed, 5 (4.5%) cases turned out to be fatal.
 Conclusions. The most effective method of introducing a cardioplegic solution in surgical interventions for aortic aneurysms combined with coronary artery lesions is the administration of cardioplegic solution antegradely, retrogradely and into alloshunts, after anastomosing thereof. This technique allows for the most effective protection of the myocardium by reducing the period of ischemia.
 In other cases, when it is impossible to introduce a cardioplegic solution antegradely (due to dissection of coronary arteries) or retrogradely (due to the presence of a persistent left superior vena cava), it is advisable to use all available alternative methods of protection and, if possible, to reduce the aortic cross-clamp time.

The Reaction of Myocardial Capillaries to Crystalloid Cardioplegia of Different Durations in Patients with Valvular Pathology and Coronary Heart Disease

The aim. To study the morphological manifestations of the response of the myocardial capillaries to cardioplegia in patients with valvular defects and coronary heart disease.
 Materials and methods. Morphological research of operative and sectional material was carried out. Myocardium fragments for microscopical study were obtained from patients at different stages of an open-heart surgery and patients who died at the stage of conservative treatment without surgical intervention. Similar samples of the myocardium of a healthy young man who died from injuries incompatible with life were studied as a control. For electron microscopy study, samples of myocardium were taken from patients at the 185th minute of perfusion.
 Results. Histological preparations of the myocardium showed pronounced diffuse hypertrophy of cardiomyocytes (CMCs), sometimes at the stage of decompensation (perinuclear edema, loss of myofibrils, apoptosis). This transformation of CMCs was obviously related to their functional overload caused by combined defects of the mitral and aortic valves. Changes in muscle fibers were accompanied by interstitial and perinuclear fibrosis. In the pool of coronary arteries affected by atherosclerosis, signs of small focal coronary fibrosis were visible, as well as rough post-infarction scars in 3 patients. All the patients had signs of acute hypoxic damage to the myocardium in the form of CMCs shortening and interstitial edema.
 Conclusions. In patients with combined defects of the aortic and mitral valves of the heart with coronary artery disease, the phenomena of myocardial fibrosis prevail. Heart valve disease combined with coronary heart disease lead to the development of both alterative and compensatory-adaptiveprocesses in the vessels of the microcirculatory bed. The greatest loss of vital organelles in small vessels is observed at 185 min after administration of cardioplegic solution, irreversible changes develop 3 h after perfusion.

Echocardiographic assessment in aortic valve insufficiency for cardioplegic solution administration.

Echocardiographic assessment in aortic valve insufficiency for cardioplegic solution administration.

Effects of the AT1 receptor blocker candesartan on myocardial ischemia/reperfusion in isolated rat hearts.

We sought to investigate the effects of the angiotension II receptor blocker candesartan on ischemia-reperfusion injury using a cardioplegia arrested isolated rat heart model. Ischemia-reperfusion injury was induced in isolated rat hearts with 40 minutes of global ischemia followed by a 30-minute reperfusion protocol. Throughout the experiment, constant pressure perfusion was achieved using a Langendorff apparatus. Cardioplegic solution alone, and in combination with candesartan, was administered before ischemia and 20 minutes after ischemia. Post-ischemic recovery of contractile function, left ventricular developed pressure, left ventricular end-diastolic pressure and contraction and relaxation rates were evaluated. In the control group, left ventricular developed pressure, rate pressure product, contraction and relaxation rates and coronary flow significantly decreased but coronary resistance increased following reperfusion. With the administration of candesartan alone, parameters did not differ compared to controls. Contractile parameters improved in the group that received candesartan in combination with the cardioplegia compared to the group that received cardioplegia alone; however, the difference between these two groups was insignificant. In this study, the addition of candesartan to a cardioplegic arrest protocol routinely performed during cardiac surgery did not provide a significant advantage in protection against ischemia-reperfusion injury compared with the administration of cardioplegic solution alone.

Difficulties in myocardial protection, tactics and surgical technique in the surgical treatment of a giant pseudoaneurysm of the ascending aorta

Abstract We present the case of a 65 years old patient, initially hospitalized at Regional Pneumology Clinic with marked fatigue, severe pulmonary symptoms (suddenly developed severe resting dyspnea, orthopnea, irritating cough), loss of appetite, weight loss and dysphagia. Chest radiography raises the suspicion of giant ascending aortic aneurysm. Echocardiography confirms the presence of the aneurysm, but CT scan with contrast and angiography showed a giant pseudoaneurysm of ascending aorta with severe local compression of the right lung hilum and right main bronchus and in posterior on the esophagus. Coronary angiography also shows significant compression and deformation of the left main coronary artery. Echocardiography reveals marked dilated ascending aorta in the suprabulbar portion without aortic insufficiency. Replacement of the ascending aorta was performed in extracorporeal circulation with a impregnated Dacron prosthesis. Because of technically difficult approach, the ascending aorta ( being the right anterolateral wall of the pseudoaneurysm) was incanculated via right axillary artery, the aortic crossclamp was performed initially transluminal with Foley catheter and later with classical metallic instruments, and myocardial protection was achieved initially by retrograde administration of cardioplegic solution with monitoring of lactic acid, pH and base excess simultaneous from coronary sinus and the coronary ostia during administration of cardioplegic solution. The postoperative evolution was favorable, the weaning from extracorporeal circulation was succeeded without inotropics, with a 48 hours length of stay in ICU, and the patient was discharged after 8 days postoperatively.

Coronary flow and reactivity, but not arrhythmia vulnerability, are affected by cardioplegia during cardiopulmonary bypass in piglets

BackgroundSurgery under cardiopulmonary bypass (CPB) is still associated with significant cardiovascular morbidity in both pediatric and adult patients but the mechanisms are not fully understood. Abnormalities in coronary flow and function have been suggested to play an important role. Prior studies suggest protective effects on coronary and myocardial function by short intravenous (i.v.) infusion of cyclosporine A before CPB.MethodsBarrier-bred piglets (10–12 kg, n=20) underwent CPB for 45 min, with or without antegrade administration of cardioplegic solution. Prior to CPB, half of the animals in each group received an i.v. infusion of 100 mg/kg cyclosporine A. The left anterior descending coronary flow velocity responses to adenosine, serotonin, and atrial pacing, as well as left ventricular function and postsurgical vulnerability to atrial fibrillation (Afib) were assessed by intracoronary Doppler, epicardial echocardiography, and in vivo electrophysiological study, before and 8 hours after surgery. Plasma C-reactive protein (CRP) and fibrinogen were measured at both time-points.ResultsCyclosporine infusion did not influence any of the studied variables (p>0.4). Coronary peak flow velocity (cPFV) rose significantly after surgery especially in the cardioplegia group (p<0.01 vs. non-cardioplegia group and pre-surgery). cPFV responses to adenosine, but not to serotonin, tended to decrease (p=0.06) after surgery only in cardioplegia group (p=0.06; p=0.8 in non-cardioplegia group vs pre-surgery). Also, cPFV response to atrial pacing was lower in the cardioplegia than in the non-cardioplegia group (p=0.02). Neither vulnerability nor duration of induced Afib after CPB differed between groups (Chi-square p=0.4). Cyclosporine had no significant effect on coronary indexes or arrhythmia vulnerability (p>0.4). There was no difference in systolic myocardial function between groups at any time point.ConclusionIn piglets, CPB with cardioplegia was associated with profound abnormalities in coronary vasomotor tone and receptor-related flow regulation, whereas arrhythmia vulnerability appeared to be comparable with that in non-cardioplegia group. In this study, preconditioning with cyclosporine had no detectable protective effect on coronary circulation or arrhythmia vulnerability after CPB.

A dental mirror provides excellent exposure of the right coronary artery during cardioplegia

It sometimes is very difficult to achieve good exposure of the orifice of the right coronary artery through a typical aortotomy when inserting the cannula for the selective antegrade administration of cardioplegic solution to the right coronary artery. A simple technique of exposing the orifice of the right coronary artery using a dental mirror is described.

Total aortic arch replacement for a patient with poor left ventricular function and patent coronary artery bypass grafts: how to establish effective myocardial protection

A 66-year-old man who had previously undergone coronary artery bypass grafting (CABG) was admitted to our institution for surgical treatment of a ruptured aortic arch aneurysm. He had three patent bypassed grafts including the left internal thoracic artery (LITA) to the left anterior descending artery (LAD), complicated by left ventricular dysfunction. Coronary angiography performed 1 year after the initial surgery revealed total occlusion of the LAD. In addition, the aneurysm was located next to the LITA; therefore, there was a significant risk of injury to the LITA during intraoperative dissection. For such a complicated and challenging case, we successfully performed a total aortic arch replacement using a Y-shaped composite saphenous vein graft (SVG) for the administration of cardioplegic solution to establish effective myocardial protection. This procedure, by which effective myocardial protection can be achieved, is a useful treatment option for aortic arch surgery after CABG with a patent LITA graft.

Late erosion of an Amplatzer septal occluder device 6 years after placement

CLINICAL SUMMARY A 46-year-old man underwent transcatheter closure of a PFO at our institution after a stroke-like event. The stretched diameter of the PFO was 9 to 10 mm. A 14-mm Amplatzer septal occluder device (AGA Medical Corporation, Golden Valley, Minn) was placed. Immediately after placement, a trivial degree of left-to-right shunt was seen through the center of the device by intracardiac echocardiography; agitated saline injection revealed a trivial right-to-left shunt. The procedure was uncomplicated, and the patient was dismissed from the hospital the following day. Predismissal transthoracic echocardiogram (TTE) showed good position and stability of the device with no apparent shunt. Ten days later, the patient returned with intermittent palpitations. Electrocardiogram revealed atrial fibrillation with rapid ventricular response. He was given intravenous diltiazem and promptly returned to sinus rhythm. TTE again documentedgoodposition of the occluder devicewith no recurrent atrial shunt or pericardial effusion. He was observed in the hospital overnight and dismissed on a regimen of oral diltiazem for 1 month. He had no recurrence of atrial fibrillation. Six years later, he came to the emergency department with progressive pleuritic chest pain. He had had similar chest pains 1month prior, which were not extensively investigated, but resolved spontaneously. In the emergency department he was hypotensive with mild jugular venous distention. TTE documented moderate pericardial effusion with tamponade. Pericardiocentesis removed 325 mL of bloody fluid. Transesophageal echocardiography did not show any evidence of shunt around the device. The device was again noted to not straddle the aortic root. Transesophageal echocardiographic

Intermittent antegrade cardioplegia: isolated heart preservation with the Asporto heart preservation device

A major problem in procurement of donor hearts is the limited time a donor heart remains viable. After cardiectomy, ischemic hypoxia is the main cause of donor heart degradation. The global myocardial ischemia causes a cascade of oxygen radical formation that cumulates in an elevation in hydrogen ions (decrease in pH), irreversible cellular injury, and potential microvascular changes in perfusion. To determine the changes of prolonged storage times on donor heart microvasculature and the effects of intermittent antegrade perfusion. Using porcine hearts flushed with a Ribosol-based cardioplegic solution, we examined how storage time affects microvascular myocardial perfusion by using contrast-enhanced magnetic resonance imaging at a mean (SD) of 6.1 (0.6) hours (n = 13) or 15.6 (0.6) hours (n = 11) after cardiectomy. Finally, to determine if administration of cardioplegic solution affects pH and microvascular perfusion, isolated hearts (group 1, n = 9) given a single antegrade dose, were compared with hearts (group 2, n = 8) given intermittent antegrade cardioplegia (150 mL, every 30 min, 150 mL/min) by a heart preservation device. Khuri pH probes in left and right ventricular tissue continuously measured hydrogen ion levels, and perfusion intensity on magnetic resonance images was plotted against time. Myocardial perfusion measured via magnetic resonance imaging at 6.1 hours was significantly greater than at 15.6 hours (67% vs 30%, P = .00008). In group 1 hearts, the mean (SD) for pH at the end of 6 hours decreased to 6.2 (0.2). In group 2, hearts that received intermittent antegrade cardioplegia, pH at the end of 6 hours was higher at 6.7 (0.3) (P = .0005). Magnetic resonance imaging showed no significant differences between the 2 groups in contrast enhancement (group 1, 62%; group 2, 40%) or in the wet/dry weight ratio. Intermittent perfusion maintains a significantly higher myocardial pH than does a conventional single antegrade dose. This difference may translate into an improved quality of donor hearts procured for transplantation, allowing longer distance procurement, tissue matching, improved outcomes for transplant recipients, and ideally a decrease in transplant-related costs.

Intermittent Antegrade Cardioplegia: Isolated Heart Preservation with the Asporto Heart Preservation Device

A major problem in procurement of donor hearts is the limited time a donor heart remains viable. After cardiectomy, ischemic hypoxia is the main cause of donor heart degradation. The global myocardial ischemia causes a cascade of oxygen radical formation that cumulates in an elevation in hydrogen ions (decrease in pH), irreversible cellular injury, and potential microvascular changes in perfusion. To determine the changes of prolonged storage times on donor heart microvasculature and the effects of intermittent antegrade perfusion. Using porcine hearts flushed with a Ribosol-based cardioplegic solution, we examined how storage time affects microvascular myocardial perfusion by using contrast-enhanced magnetic resonance imaging at a mean (SD) of 6.1 (0.6) hours (n = 13) or 15.6 (0.6) hours (n = 11) after cardiectomy. Finally, to determine if administration of cardioplegic solution affects pH and microvascular perfusion, isolated hearts (group 1, n = 9) given a single antegrade dose, were compared with hearts (group 2, n = 8) given intermittent antegrade cardioplegia (150 mL, every 30 min, 150 mL/min) by a heart preservation device. Khuri pH probes in left and right ventricular tissue continuously measured hydrogen ion levels, and perfusion intensity on magnetic resonance images was plotted against time. Myocardial perfusion measured via magnetic resonance imaging at 6.1 hours was significantly greater than at 15.6 hours (67% vs 30%, P = .00008). In group 1 hearts, the mean (SD) for pH at the end of 6 hours decreased to 6.2 (0.2). In group 2, hearts that received intermittent antegrade cardioplegia, pH at the end of 6 hours was higher at 6.7 (0.3) (P = .0005). Magnetic resonance imaging showed no significant differences between the 2 groups in contrast enhancement (group 1, 62%; group 2, 40%) or in the wet/dry weight ratio. Intermittent perfusion maintains a significantly higher myocardial pH than does a conventional single antegrade dose. This difference may translate into an improved quality of donor hearts procured for transplantation, allowing longer distance procurement, tissue matching, improved outcomes for transplant recipients, and ideally a decrease in transplant-related costs.

Beating Heart Mitral Valve Replacement with a Bovine Pericardial Bioprosthesis for Treatment of Mitral Valve Dysplasia in a Bull Terrier

To describe an open, beating heart surgical technique and use of a bovine pericardial prosthetic valve for mitral valve replacement (MVR) in the dog. Clinical case report. Male Bull Terrier (17-month-old, 26 kg) with mitral valve dysplasia and severe regurgitation. A bovine pericardial bioprosthesis was used to replace the mitral valve using an open beating heart surgical technique and cardiopulmonary bypass. Successful MVR was achieved using a beating heart technique. Mitral regurgitation resolved and cardiac performances improved (left ventricular end-diastolic diameter decreased from 57.6 to 48.7 mm, and left atrium/aorta ratio returned to almost normal, from 1.62 to 1.19). Cardiopulmonary by-pass time and total surgical duration were decreased compared with standard cardioplegic techniques. Surgical recovery was uneventful and on echocardiography 6 months later valve function was excellent. Considering the technique advantages (no cardiac arrest, ischemic reperfusion injury, and hypothermia, or the need for aortic dissection and cannulation for administration of cardioplegic solution), short-term mortality and morbidity may be reduced compared with standard cardioplegic techniques. Based on experience in this dog, beating heart mitral valvular replacement is a seemingly safe and viable option for the dog and bovine pericardial prosthesis may provide better long-term survival than mechanical prostheses.

Feasibility Study of a Direct Endo-Aortic Clamp Balloon

We have developed a new end-aortic clamp balloon catheter intended to be inserted directly into, thereby occluding, the ascending aorta. We examined the performance of this catheter in a canine model. We evaluated the extent of migration tolerance of the catheter under cardiopulmonary bypass perfusion in 12 mongrel dogs, weighing 20 kg, under general anesthesia. After institution of cardiopulmonary bypass, this catheter was inserted into the ascending aorta, and the balloon was inflated to occlude the ascending aorta. After the canine heart was arrested following the administration of cardioplegic solution, balloon migration was examined over a period of 3 hours, with hourly increases in perfusion pressure from 50 mm Hg to 80 mm Hg and finally to 100 mm Hg. After the migration test, ascending aortic wall sections, where the balloon was inflated, were examined microscopically. At internal balloon pressure of 300 to 400 mm Hg, migration occurred at perfusion pressure of > or =90 to 100 mm Hg. No histological differences were observed with use of the balloon catheter, compared with an extra-aortic clamp forceps. Based on these results, this device is safe, feasible, and can adequately occlude the ascending aorta during cardiopulmonary bypass. We conclude that this device is effective in patients weighing 20 kg.

A Technique for Infusion of Cardioplegic Solution in Coronary Artery Bypass with Aortic Regurgitation

Complications such as heart failure due to insufficient cardioplegia may develop in on-pump coronary artery bypass (CAB) with mild-to-moderate aortic regurgitation (AR). A technique for administration of cardioplegic solution was carried out to avoid such complications. Cardiopulmonary bypass was established. After aortic cross-clamping, cardioplegic solution was administered from aortic root. Because complete cardiac arrest was not rapidly achieved, the aortic root was incised. Three cusps of the aortic valve were sutured. The aorta was closed; cardioplegic solution was administered from the aortic root. Then, cardiac arrest was rapidly achieved. After distal anastomosis of quadruple bypass was completed, the suture of the cusps was removed. There was no exacerbation of AR due to this method compared to the preoperative state. When off-pump coronary artery bypass is impossible and retrograde cardioplegia cannot be performed for a certain reason, this method may be set to one of the choices.

Monitoring aortic root effluent during retrograde cardioplegia delivery.

Continuous monitoring of myocardial protection during aortic crossclamping is not always performed, due to limitations with current technology. The purpose of this study was to use readily available technology to evaluate the effectiveness of retrograde cardioplegia delivery by monitoring the aortic root vent effluent. The CDI 400, a commonly used blood monitoring device, was used to monitor changes in temperature, pO2, pCO2, and pH by placing a 1/4-inch CDI Quick Cell and probe in the aortic root vent line prior to each case. Twenty adult patients undergoing coronary bypass surgery were involved in the study, which resulted in 48 doses of retrograde cardioplegic solution. The study revealed a significant correlation between the temperature of the cardioplegia solution and the temperature of the aortic root effluent (p < 0.001. r = 0.88). The cardioplegia temperature did not correlate with the change in effluent pO2 (p = NS) or the degree of effluent temperature change (p = NS). Furthermore, the change in effluent temperature was not influenced by the amount of cardioplegia solution delivered (p = NS), or the time between administrations (p = NS). Both the decreasing and increasing trends of the effluent pO2 significantly correlated with the cardioplegia solution flow rate (p = 0.034, r = 0.32 and p = 0.013, r = 0.37, respectively), but not with the time between doses (p = NS) or volume of cardioplegia solution delivered (p = NS). The increase in effluent pO2 did correlate with the coronary sinus pressure (p < 0.001, r = 0.48). Measuring aortic root vent effluent may be used to assure the successful delivery of retrograde cardioplegic solution and aid in the detection of various procedural problems. Once the trends from this technique are established by the surgical team, they may be used to adjust cardioplegic solution administration and provide documentation of myocardial protection.

Deoxygenated blood minimizes adherence of sonicated albumin microbubbles during cardioplegic arrest and after blood reperfusion: Experimental and clinical observations with myocardial contrast echocardiography

Both administration of cardioplegic solution and blood reperfusion result in endothelial dysfunction. The transit rate of albumin microbubbles during myocardial contrast echocardiography may reflect endothelial injury. Accordingly, we performed myocardial contrast echocardiography in 12 dogs undergoing cardiopulmonary bypass and measured the myocardial transit rate of microbubbles injected into the aortic root during delivery of cardioplegic solutions containing arterial and venous blood and delivery of pure crystalloid cardioplegic solution. The myocardial transit rate of 99mTc-labeled red blood cells was measured and perfusates were sampled for biochemical analysis at each stage. The microbubble transit rate was markedly prolonged during delivery of crystalloid cardioplegic solution and improved significantly during infusion of blood cardioplegic solution ( p < 0.001); venous compared with arterial blood in the solution resulted in a greater rate ( p < 0.001). The microbubble transit rate did not correlate with pH, oxygen tension or carbon dioxide tension values, or K + concentration. The red blood cell transit rate remained constant regardless of the cardioplegic perfusate infused. Myocardial contrast echocardiography was also performed in 12 patients undergoing coronary artery bypass who underwent sequential arterial and venous reperfusion after cardioplegic arrest. The microbubble transit rate was faster with venous than arterial blood reperfusion ( p = 0.01), although this gain was diminished when arterial blood reperfusion preceded venous blood reperfusion ( p = 0.05). Our results indicate that endothelial dysfunction after cardioplegic arrest may be ameliorated by reperfusion with venous rather than arterial blood. (J Therac Cardiovasc Surg 1997;113:1100-8)

Antegrade versus Retrograde Cardioplegia for Uncomplicated Coronary Artery Disease: A Comparative Study

Since the introduction of the retrograde administration of cardioplegic solutions in cardiac surgery in the mid-1980's, the technique has been widely adopted for routine use in high risk patients with impaired ventricular function, based on favorable results demonstrated in clinical series. However, we sought to evaluate the benefits of routine use of this method in low risk patients by means of a retrospective review of 34 consecutive non-repeat, isolated coronary artery bypass grafting patients with left ventricular ejection fractions &gt; 35%. Seventeen patients received intermittent ante grade cardioplegia exclusively and 17 received ante grade induction followed by intermittent retrograde cardioplegia maintenance. No significant baseline differences were found between the two groups. There were no deaths or major complications in either group. Retrograde cardioplegia patients had significantly lower pulmonary artery diastolic pressures in the first 24 hours postoperatively, accompanied by a non-significant trend toward higher cardiac indices during this same period. Phenylephrine infusions were used more frequently during the postoperative period in the retrograde group (p = 0.021). Fewer pulmonary complications were seen in the retrograde cardioplegia group (p=0.042), in addition to non-significant trends toward less atrial arrhythmias and less hospital days. No adverse effects or increased operative time could be attributed to the retrograde administration of cardioplegic solution in this study population. Based on the results from this small clinical series, retrograde cardioplegia administration offers distinct advantages for myocardial protection in low risk coronary bypass patients, as manifested by improved postoperative hemodynamic performance, with no significant adverse effects. A prospective, randomized trial of this technique in a larger, similar patient population is likely to show even more compelling positive results favoring the routine use of retrograde administration of cardioplegic solutions.

Free radical reaction products and antioxidant capacity in arterial plasma during coronary artery bypass grafting

Oxygen free radicals mediate the ischemia-reperfusion damage in animal hearts, but their role in human beings is still controversial because of the low xanthine oxidase level in the human heart. Besides ischemia-reperfusion, cardiac operation also includes other major interventions that might generate free radicals but have not been systematically studied. We studied the cases of nine patients throughout coronary artery operations, including general anesthesia, heparin, protamine and administration of cardioplegic solution, extracorporeal circulation, and heart reperfusion. Arterial plasma was assayed for malondialdehyde, diene conjugates, and fluorescent chromolipids, and plasma antioxidant activity was estimated from the ability to trap peroxyl radicals. Anesthesia, surgical procedures, or heparin administration did not change these parameters. Extracorporeal circulation decreased the plasma concentration of diene conjugates immediately, whereas other compounds remained unaltered. When these concentrations were corrected for hemodilution, the amount of fluorescent chromolipids actually increased after 5 minutes of extracorporeal circulation to 177% ± 14% (mean ± standard error of the mean), diene conjugates increased to 138% ± 12%, and plasma antioxidant capacity increased to 144% ± 12% of the awake value. Fluorescent chromolipid values remained at 156% to 177% throughout the perfusion and decreased to 130% ± 13% 1 hour after perfusion. Diene conjugate levels and antioxidant capacity were 123% to 144% and 143% to 161%, respectively, from baseline during perfusion and 119% ± 5% and 135% ± 9%, respectively, 1 hour after perfusion. Heart reperfusion or protamine administration showed no additional increases. Malondialdehyde concentrations varied and showed no statistically significant alterations. We conclude that extracorporeal circulation devices induce generation of free radicals and plasma antioxidant activity, which are different from the damage caused by ischemia-reperfusion. (J THORAC CARDIOVASC SURG 1994; 108:140-7)

Quantitative effects of myocardial edema on the left ventricular pressure-volume relation: Influence of cardioplegia osmolarity over two hours of ischemic arrest

We previously studied edema and left ventricular pressure-volume relations in a porcine heart model in which edema occurred even with hyperosmolar crystalloid cardioplegia. This susceptibility to edema was attributed to venous occlusion and an initial 20-minute period of ischemia. Results did not demonstrate reversal of edema by hyperosmolar perfusates. Accordingly, in the present study, heart weight, myocardial water content, and left ventricular pressure-volume curves were measured before and after perfusion-induced edema in eight isolated, arrested, hypothermic porcine hearts. Cardioplegic solution was infused 2.1 +/- 0.8 minutes after the onset of ischemia, and the atrioventricular ring was not clamped during the administration of cardioplegic solution. Cardioplegic solution (1 L) was infused at intervals of 33 +/- 6 minutes at 4 degrees C. Solution osmolarity was 380 (Stanford solution) or 294 mOsm/L (Plegisol solution). The perfusion sequence was 380-1, 380-2, 294-1, 380-3. Pressure-volume relations were assessed with the use of left ventricular volume at a pressure of 10 mm Hg and the ventricular chamber stiffness constant, beta, derived from P = alpha e beta V. Perfusions 380-1 and 380-2 did not affect the pressure-volume curve. Perfusion 294-1 increased heart weight and water content (p < 0.05) and decreased left ventricular volume at 10 mm Hg compared with perfusions 380-1, 380-2, and 380-3. In addition, beta increased (0.023 +/- 0.005 versus 0.029 +/- 0.006, p < 0.05) after perfusion 294-1, compared with 380-1. Correlation coefficients for linear regressions between left ventricular volume at 10 mm Hg and heart weight and water content were r = 0.84 and r = 0.70, respectively. We conclude that under conditions similar to those used clinically, the left ventricle of the pig does not develop edema with Stanford solution (380 mOsm/L). Edema does follow Plegisol solution (294 mOsm/L) cardioplegia. Edema and reduced compliance are incompletely reversed by hypertonic cardioplegia. The porcine left ventricle can usefully replicate the clinical model.