Wolff-Parkinson-White syndrome with an unroofed coronary sinus without persistent left superior vena cava treated with catheter cryoablation

Coronary sinus anomalies are rare congenital defects which are usually coexistent with a persistent left superior vena cava and may be associated with cardiac arrhythmias. We report an unroofed coronary sinus without persistent left superior vena cava diagnosed during a catheter ablation procedure for Wolff-Parkinson-White syndrome. Diagnostic and therapeutic options and outcomes are discussed. This condition is of relevance to electrophysiologists performing catheter-based procedures, as well as cardiologists implanting coronary sinus pacing leads, who may encounter this anomaly in their practice.     

Acidaemia reduces cardiac output and left ventricular contractility in conscious lambs

We studied the effects of HCI-induced metabolic acidaemia on cardiac output, contractile function, myocardial blood flow, and myocardial oxygen consumption in nine unanaesthetized newborn lambs. Through a left thoracotomy, catheters were placed in the aorta, left atrium and coronary sinus. A pressure transducer was placed in the left ventricle. Three to four days after surgery, we measured cardiac output, dP/dt, left ventricular end diastolic and aortic mean blood pressures, heart rate, aortic and coronary sinus blood oxygen contents, and left ventricular myocardial blood flow during a control period, during metabolic acidaemia, and after the aortic pH was restored to normal. We calculated systemic vascular resistance, myocardial oxygen consumption and left ventricular work. Acidaemia was associated with reduction in cardiac output, maximal dP/dt, and aortic mean blood pressure. Left ventricular end diastolic pressure and systemic vascular resistance increased, and heart rate did not change significantly. The reduction in myocardial blood flow and oxygen consumption was accompanied by fall in cardiac work. Cardiac output returned to control levels after the pH had been normalized but maximal dP/dt was incompletely restored. Myocardial blood flow and oxygen consumption increased beyond control levels. This study demonstrates that HCI-induced metabolic acidaemia in conscious newborn lambs is associated with a reduction in cardiac output which could have been mediated by the reduction in contractile function and/or the increase in systemic vascular resistance. The decreases in myocardial blood flow and oxygen consumption appear to reflect diminished cardiac work. The restoration of a normal cardiac output after normalization of the pH appears to have resulted from the increases in heart rate and left ventricular filling pressures in conjunction with an incomplete restoration of contractile function.     

A method of continuous registration of heat production of the heart

A new method of continuous registration of the cardiac heat production was developed for the quantitative assessment of the levels of metabolic processes in cardiac hemodynamic reactions. The method is based on the technique of coronary arteries catheterization and extracorporeal perfusion, coronary sinus catheterization with a special catheter equipped with miniature-temperature transducer and a device designed for transformation of blood temperature values into the electrical signals. The data on the changes in cardiac heat production during cardiovascular adrenergic reactions and in conditions of acute myocardial ischemia have been obtained. It has been shown that changes in myocardial heat production depend significantly on the direction of shifts in the cardiac function and associated alterations in the level of myocardial metabolic processes.     

A technique for measurement of retrograde coronary blood flow in intact anesthetized dogs.

A technique for measurement of retrograde coronary blood flow in intact anesthetized dogs is described. Occlusion of the coronary artery is produced by the inflation of a small rubber balloon at the tip of a no. 9 cardiac catheter placed under fluorescopy in a branch of the left coronary artery. Blood which bleeds back from the occluded coronary artery through the no. 9 catheter is diverted into a small reservoir of 1-ml capacity. The time to fill this reservoir is recorded electrically. Retrograde coronary blood flow is calculated from the time required to fill this reservoir. Results indicate good repeatability of meadurements. The technique seems to be a simple, adequate, and convenient means for assessing agents for possible vasodilator action on the collateral circulation in intact animals.     

Safety of mapping in the sinus of valsalva region under intracardiac echocardiography guidance without angiography

BackgroundRadiofrequency ablation at the region of the sinus of Valsalva carries a risk to the ostia of the coronary arteries. Coronary angiography is usually utilized to document a safe distance for mapping and ablation.ObjectiveTo show that catheter ablation in the aortic root could be guided by phased-array intra cardiac echocardiography (ICE) and electro anatomic mapping without the need for coronary angiography.MethodsWe reviewed all patients referred to our lab that underwent mapping and/or ablation in the sinus of Valsalva region. Procedures were carried out by operators that are skilled in the use of ICE. The need for angiography was documented, also the rate of success along with the immediate and 30-day complications rate.ResultsSeventy patients (average age 48.7 ± 13.8 years; 64.3% males) were referred for ablation of ventricular and atrial arrhythmias. PVC constituted 95.7% of the cases. All patients underwent mapping and/or ablation at the sinus of Valsalva region without the need for coronary angiography to visualize the coronary ostia. Acute and effective ablation was achieved in 57 out of 70 (81.4%) patients partially effective ablation was achieved in 10 (14.3%) patients, and failure to ablate in the remaining 3 patients (4.3%). There was no occurrence of any adverse events, neither immediately or at day 30 after the procedure.ConclusionIn the hands of experienced operators, mapping and radiofrequency ablation in the sinus of Valsalva can be safely and reliably performed using intracardiac echocardiography alone without the need for supplementary catheter coronary angiography.     

A METHOD OF CORONARY RETROPERFUSION FOR THE TREATMENT OF ACUTE MYOCARDIAL ISCHEMIA

A method of retrograde perfusion of the myocardium has been developed in dogs. It consists of a double lumen balloon-tipped catheter inserted transvenously into the coronary sinus, with one lumen connected to a roller pump, the other to a helium counterpulsing pump. Oxygenated heparinized blood is obtained from the femoral artery and pumped continuously into the coronary sinus at a pressure of 50-75 mm Hg. The balloon is inflated during diastole, sealing the coronary sinus and promoting retrograde flow, and is deflated during systole, allowing blood drainage into the right atrium and preventing venous congestion. Thirteen anesthetized open-chest dogs were subjected to 15 minutes of proximal LAD artery occlusion and 30 minutes of diastolic coronary sinus perfusion (DCSP). The area of ischemia was mapped by means of platinum electrodes capable of simultaneously measuring myocardial tissue oxygen tension M(p)O(2)) and electrograms. Reduction of M(p)O(2) with simultaneous elevation of the ST segment on the corresponding electrogram was considered an indication of ischemia. Diastolic coronary sinus perfusion improved myocardial oxygen tension in the ischemic myocardium, reduced ST segment elevation, and tended to restore arterial blood pressure. Histologically, there was no intramyocardial hemorrhage.     

Continuous measurement of aortic blood velocity,after cardiac surgery,by means of an extractable doppler ultrasound probe

A new method has been developed for the continuous measurement of aortic blood velocity in patients following cardiac surgery. Using an extractable Doppler ultrasound probe placed on the ascending aorta, the changes in aortic velocity were recorded up to 24 h postoperatively, in 14 patients undergoing coronary bypass surgery. Volume flow rate is calculated from the mean velocity, the diameter of the aorta and the angle between the ultrasound beam and the direction of the blood flow, by means of an analogue flow calculator. Estimation of aortic flow showed a correlation of r = 0.79 with cardiac output measured by a thermodilution technique. The main advantage of the system is that it allows continuous monitoring of cardiac output, as well as short and long-term trend analyses, during the early postoperative period.     

Single coronary artery with transeptal anterior interventricular artery: a rare anatomical feature

A case of a single coronary artery is described in a 50-year-old male, who died of asphyxia. The artery originated in the right aortic sinus and from it another artery emerged which crossed the crista supraventricularis and the interventricular septum and returned to occupy a subepicardial position in the lower half of the anterior interventricular sulcus. This partially intramyocardial artery was considered as the anterior interventricular artery. A literature survey showed only five cases with similar characteristics. The importance of this anomaly derives from the risk of damage occurring to the intramyocardial artery during a manipulation of the infundibulum of the right ventricle in a cardiac surgery or from problems of perfusion during coronary bypass procedures.     

Video-Assisted Implantation of a Left Ventricular Lead and Intrathoracic Tunneling to a Right-Sided CRT-D Device

We describe two cases in which a biventricular implantable cardioverter defibrillator for cardiac resynchronization therapy had to be placed on the right side due to unsuitability of the left subclavian vein. Endocardial implantation of a left ventricular lead through the coronary sinus was previously attempted but was unsuccessful. Implantation of the epicardial left ventricular pacing lead was performed through video-assisted thoracic surgery on the left side. The connector end of the left ventricular pacing lead was tunnelized through the anterior mediastinum into the right pleural space. The right-sided pocket was then opened. A tunnel was created from the pocket to the thoracic wall, and the pleural space was entered over the second rib. The lead was retrieved from the right pleural space and connected with the Cardiac resynchronization therapy-device (CRT-D). Both procedures and postoperative periods were uneventful. Intrathoracic left-to-right tunneling of an epicardial left ventricular lead by video-assisted thoracic surgery is feasible and safe. It provides an alternative to subcutaneous tunneling.     

Inflammatory cytokines and soluble receptors after coronary artery bypass grafting

Much interest has been focused on the overexpression of proinflammatory cytokines, but studies on their soluble receptors are rare. For a comprehensive picture of cytokine activation in cardiac surgery, a combination of cytokines and the corresponding soluble receptor concentration should be determined. Blood samples were collected from the radial artery and coronary sinus perioperatively in ten patients undergoing coronary artery bypass grafting with cardiopulmonary bypass. TNF-alpha, IL-6, sTNFRI, sTNFRII, and sIL-6R levels in the plasma were determined. Systemic TNFRI, TNFRII and IL-6 increased significantly after reperfusion to the myocardium, while perioperative systemic sIL-6r levels were similar. Arterial and sinus levels of TNFRI, TNFRII and sIL-6r were similar before cardiopulmonary bypass. Five minutes after reperfusion to the myocardium, higher sinus TNFRI and TNFRII and lower sinus sIL-6R levels were observed as compared to the arterial levels. The myocardium release of sTNFRI (r=0.57, P=0.089) and sTNFRII (r=0.64, P=0.047) positively correlated with the change of cardiac index after cardiopulmonary bypass. Myocardium releases sTNFRI and sTNFRII after ischaemic-reperfusion injury, and this may be of benefit to cardiac performance. sIL-6R is constantly being produced in areas other than the myocardium, while sIL-6R levels are reduced by consumption in the myocardium after ischaemic-reperfusion injury.     

Snare technique for coronary sinus cannulation in cardiac resynchronization therapy

PurposeBiventricular pacing is a mainstay of therapy for patients with heart failure. However, lead implantations may fail due to anatomical reasons including the impossibility of coronary sinus cannulation.Methods and resultsA dual approach from the subclavian vein using a snare through a sheath and from the femoral vein using a steerable electrophysiology catheter was performed. Once the snare hooked the catheter, the latter was advanced into the coronary sinus and finally, the sheath could also be advanced in an “over-the-wire” technique.ConclusionThe snare technique for coronary sinus cannulation offers a “bail-out” strategy for left ventricular lead implantation.     

Successful ablation of a left-sided accessory pathway in a patient with coronary sinus atresia and arteriovenous fistula: clinical and developmental insights

Background and objectives

While radiofrequency ablation catheter ablation of accessory pathways is generally safe and effective, anatomic variants can cause considerable challenges in effecting cure. Our objective was to use an unusual case where coronary sinus was absent and arterial venous fistula was present and a left-sided pathway required mapping and ablation to develop a framework to approach difficult cases.

Method

A detailed literature search and review of contemporary cardiac embryology was undertaken to attempt and to explain a common developmental anomaly. Adjunctive approaches during the ablation procedure, including intracardiac ultrasound, were used to guide mapping and ablation despite the lack of coronary sinus access.

Results

The accessory pathway was successfully ablated using a transseptal approach and intracardiac ultrasound guided mapping of the mitral annulus. A potential common mechanism to explain the apparently disparate anatomic variants in this patient was formulated.

Conclusions

Cardiac conduction development is complex and accessory pathway conduction may occur in the setting of arteriovenous anomalies thus providing insights as to the cause of WPW syndrome. Successful mapping and targeted ablation of left-sided pathways may be accomplished even when coronary sinus access is not possible.     

A New Coronary Retroinfusion Technique in theRat Infarct Model: Transjugular Cardiac Vein Catheterization

Cell delivery via the retrograde coronary route boasts less vessel embolism, myocardial injury, and arrhythmogenicity when compared with those via antegrade coronary administration or myocardial injection. However, conventional insertion into the coronary sinus and consequent bleeding complication prevent its application in small animals. To overcome the complication of bleeding, we described a modified coronary retroinfusion technique via the jugular vein route in rats with myocardial infarction (MI). A flexible wire with a bent end was inserted into the left internal jugular vein and advanced slowly along the left superior vena cava. Under direct vision, the wire was run into the left cardiac vein by rotating the wire and changing the position of its tip. A fine tube was then advanced along the wire to the left cardiac vein. This modified technique showed less lethal hemorrhage than the conventional technique. Retroinfusion via transjugular catheter enabled efficient fluid or cell dissemination to the majority areas of the free wall of the left ventricle, covering the infarcted anterior wall. In conclusion, transjugular cardiac vein catheterization may make retrocoronary infusion a more safe and practical route for delivering cell, drug, and gene therapy into the infarcted myocardium of rats.     

Coronary venous flow and O2 saturation during transitional phases between various cardiac rates.

The instantaneous and continuous interrelationship between coronary blood flow and coronary venous O2 saturation was determined during transient periods following abrupt rate change in the electrically paced canine heart. Through a catheter in the coronary sinus, O2 saturation was continuously monitored using a fibreoptics technique, and venous flow was measured with an electromagnetic flowmeter. Various patterns of change in flow and O2 saturation were observed depending both on the absolute values of the cardiac rates as well as on the relative difference between them during changes from one rate to another. Whereas elevation of coronary flow was monophasic when the magnitude of heart rate change was below 75 beats per minute, a drop in flow was observed preceeding its elevation when the difference was greater. At high rates further increase in rate caused either no alteration or led to a monophasic drop in flow during the transitional period. Changes in O2 saturation were observed only when heart rate difference exceeded 60 beats per minute. Between 60-90 beats per minute O2 saturation remained steady except during the transient rate elevation, ending in a lower steady state O2 saturation. The results indicate that both O2 saturation and coronary flow change with heart rate initially because of mechanical consequence of the increased rate on the myocardium, and later according to its new metabolic needs also manifested by changed O2 extraction.     

Surgical Placement of Catheters for Long-term Cardiovascular Exercise Testing in Swine

This protocol describes the surgical procedure to chronically instrument swine and the procedure to exercise swine on a motor-driven treadmill. Early cardiopulmonary dysfunction is difficult to diagnose, particularly in animal models, as cardiopulmonary function is often measured invasively, requiring anesthesia. As many anesthetic agents are cardiodepressive, subtle changes in cardiovascular function may be masked. In contrast, chronic instrumentation allows for measurement of cardiopulmonary function in the awake state, so that measurements can be obtained under quiet resting conditions, without the effects of anesthesia and acute surgical trauma. Furthermore, when animals are properly trained, measurements can also be obtained during graded treadmill exercise.Flow probes are placed around the aorta or pulmonary artery for measurement of cardiac output and around the left anterior descending coronary artery for measurement of coronary blood flow. Fluid-filled catheters are implanted in the aorta, pulmonary artery, left atrium, left ventricle and right ventricle for pressure measurement and blood sampling. In addition, a 20 G catheter is positioned in the anterior interventricular vein to allow coronary venous blood sampling.After a week of recovery, swine are placed on a motor-driven treadmill, the catheters are connected to pressure and flow meters, and swine are subjected to a five-stage progressive exercise protocol, with each stage lasting 3 min. Hemodynamic signals are continuously recorded and blood samples are taken during the last 30 sec of each exercise stage.The major advantage of studying chronically instrumented animals is that it allows serial assessment of cardiopulmonary function, not only at rest but also during physical stress such as exercise. Moreover, cardiopulmonary function can be assessed repeatedly during disease development and during chronic treatment, thereby increasing statistical power and hence limiting the number of animals required for a study.     

Anatomical and functional characteristics of carotid sinus stimulation in humans

Transmission characteristics of pneumatic pressure to the carotid sinus were evaluated in 19 subjects at rest and during exercise. Either a percutaneous fluid-filled (n = 12) or balloon-tipped catheter (n = 7) was placed at the carotid bifurcation to record internal transmission of external neck pressure/neck suction (NP/NS). Sustained, 5-s pulses, and rapid ramping pulse protocols (+40 to -80 Torr) were recorded. Transmission of pressure stimuli was less with the fluid-filled catheter compared with that of the balloon-tipped catheter (65% vs. 82% negative pressure, 83% vs. 89% positive pressure; P < 0.05). Anatomical location of the carotid sinus averaged 3.2 cm (left) and 3.6 cm (right) from the gonion of the mandible with a range of 0-7.5 cm. Transmission was not altered by exercise or Valsalva maneuver, but did vary depending on the position of the carotid sinus locus beneath the sealed chamber. These data indicate that transmission of external NP/NS was higher than previously recorded in humans, and anatomical variation of carotid sinus location and equipment design can affect transmission results.     

Surgical Ablation for Atrial Fibrillation in Cardiac Surgery: A Consensus Statement of the International Society of Minimally Invasive Cardiothoracic Surgery (ISMICS) 2009

OBJECTIVE:: This purpose of this consensus conference was to determine whether surgical atrial fibrillation (AF) ablation during cardiac surgery improves clinical and resource outcomes compared with cardiac surgery alone in adults undergoing cardiac surgery for valve or coronary artery bypass grafting. METHODS:: Before the consensus conference, the consensus panel reviewed the best available evidence, whereby systematic reviews, randomized trials, and nonrandomized trials were considered in descending order of validity and importance. Evidence-based statements were created, and consensus processes were used to determine the ensuing recommendations. The American Heart Association/American College of Cardiology system was used to label the level of evidence and class of recommendation. RESULTS:: The consensus panel agreed on the following statements in patients with AF undergoing cardiac surgery concomitant surgical ablation: CONCLUSIONS:: Given these evidence-based statements, the consensus panel stated that, in patients with persistent and permanent AF undergoing cardiac surgery, concomitant surgical ablation is recommended to increase incidence of sinus rhythm at short- and long-term follow-up (class 1, level A); to reduce the risk of stroke and thromboembolic events (class 2a, level B); to improve EF (class 2a, level A); and to exercise tolerance (class 2a, level A) and long-term survival (class 2a, level B).     

Marshall to the rescue in cardiac resynchronization therapy: Left ventricular lead placement in coronary sinus ostial atresia

This case highlights the importance of proper identification of congenital anomalies of the coronary sinus for the successful placement of left ventricular lead during cardiac resynchronization therapy device implantation. We discuss an alternate route for left ventricular lead placement via the vein of Marshall when the coronary sinus ostium in the right atrium was atretic and was facing difficulty initially in detecting the anomaly.     

An ultrafiltration catheter for monitoring of venous lactate and glucose around myocardial ischemia

Early detection of myocardial ischemia is of major importance in critical-care medicine. Changes of lactate or glucose levels in the cardial venous efflux may be useful parameters. We succeeded in integrating an ultrafiltration membrane in a cardiac catheter for continuous sampling. The ultrafiltrate was analyzed outside the body, resulting in a lag-time of about 24 min. Biosensors in a flow-injection analysis system were used for minute by minute sample analyses. The coronary sinus of pigs was catheterized to monitor the effects of 5, 15 or 45 min ischemia by coronary artery obstruction or myocardial stress by dobutamine infusion. A total of 27 h was monitored. The intravascular response time was 1.33+/-0.61 min (10-90%). Linear regression in vivo of blood and ultrafiltrate samples was 0.977 for lactate and 0.994 for glucose. Lactate levels rose 0.38+/-0.10 mM above baseline within 5 min after ischemia. Reperfusion was clearly marked by a promptly peaking lactate release (maximum 9.27 mM). Myocardial stress by dobutamine increased glucose but not lactate levels. Once, a wall effect was noted at the catheter tip. In vivo semi-continuous myocardial monitoring of absolute lactate and glucose concentrations was thus achieved by an ultrafiltration catheter. Ischemia and reperfusion can be detected very early by a lactate level rise. Further, development of the ultrafiltration catheter will be focused on the diagnostic potential of lactate monitoring for patients.     

Comparison of Conventional versus Steerable-Catheter Guided Coronary Sinus Lead Positioning in Patients Undergoing Cardiac Resynchronization Device Implantation

Objectives

The aim of this study was to compare conventional versus steerable catheter guided coronary sinus (CS) cannulation in patients with advanced heart failure undergoing cardiac resynchronization therapy (CRT).

Background

Steerable catheter guided coronary sinus cannulation could reduce fluoroscopy time and contrast medium use during CRT implantation.

Methods

176 consecutive patients with ischemic and non-ischemic heart failure undergoing CRT implantation from January 2008 to December 2012 at the University Hospital of Cologne were identified. During the study period two concurrent CS cannulation techniques were used: standard CS cannulation technique (standard-group, n = 113) and CS cannulation using a steerable electrophysiology (EP) catheter (EPCath-group, n = 63). Propensity-score matched pairs of conventional and EP-catheter guided CS cannulation made up the study population (n = 59 pairs). Primary endpoints were total fluoroscopy time and contrast medium amount used during procedure.

Results

The total fluoroscopy time was 30.9 min (interquartile range (IQR), 19.9–44.0 min) in the standard-group and 23.4 min (IQR, 14.2-34-2 min) in the EPCath-group (p = 0.011). More contrast medium was used in the standard-group (60.0 ml, IQR, 30.0–100 ml) compared to 25.0 ml (IQR, 20.0–50.0 ml) in the EPCath-group (P<0.001).

Conclusions

Use of steerable EP catheter was associated with significant reduction of fluoroscopy time and contrast medium use in patients undergoing CRT implantation.