Andrew R. J. Mitchell

Trends in management of acute cholecystitis.

A retrospective review has been carried out of the management of acute cholecystitis in one hospital from 1974 to 1978. The policies and outcome are compared with those of the same centre during 1953-62. In the intervening period there has been a move towards early cholecystectomy. Overall mortality has fallen from 7.7% to 1.6%. The results of early surgery are comparable with those of delayed operations. The data also compare favourably with those of controlled clinical trials and support the adoption of early cholecystectomy for acute cholecystitis in routine practice. The saving of resources, however, may not be as great as is suggested by the results of clinical trials.

Single Centre Experience with GORE-HELEX Septal Occluder for Closure of PFO

Several devices are available for percutaneous patent foramen ovale (PFO) closure. Over the past 3 years our planned treatment strategy of PFO closure has been routine use of the GORE-HELEX septal occluder device, followed by 6 months of aspirin therapy. We present the safety and feasibility of routinely using this device for all patients undergoing percutaneous PFO closure, with 3-month transthoracic echocardiogram (TTE) follow up. In total, 75 adult patients (44.0+/-11.7 years; 45.3% male) were referred for PFO closure during the study period. All patients underwent echocardiography prior to PFO closure. In 5 patients no PFO was found, and 1 patient had an atrial secundum defect closed using the Amplatzer septal occluder. Of the 69 remaining patients with PFO, 68/69 (98.6%) underwent closure with the GORE-HELEX device. Six of 69 cases required device retrieval and 5 of 6 were replaced successfully with a second GORE-HELEX device. One of the 6, a large PFO associated with atrial septal aneurysm, was replaced using the Amplatzer septal occluder. There were no major complications. At 3-month follow up, 65/68 (95.6%) had no residual shunt on TTE, and 3 patients had small residual shunts thought to be related to incomplete endothelialisation at 3 months. In conclusion, percutaneous PFO closure using the GORE-HELEX septal occluder device is safe and feasible, with no major peri-procedural complications and excellent short-term results at 3-month follow up.

Pharmacological Management of No Reflow During Percutaneous Coronary Intervention

Angiographic no reflow is a recognized phenomenon during percutaneous coronary intervention (PCI). It usually follows successful lesion dilation and, by definition, it represents a reduction in epicardial coronary blood flow in the absence of identifiable dissection, obstruction or distal vessel cut off (indicative of distal embolisation). No reflow appears to be more commonly associated with PCI for acute myocardial infarction and PCI for saphenous vein graft occlusions. While the exact mechanism of no reflow is unknown, theoretical causes include local humoral and microembolic effects leading to microcirculatory dysfunction. As the process is multifactorial, various therapeutic strategies are required in different situations. The present day pharmacological management involves the use of vasodilators including nitrates, verapamil, papaverine, adenosine, nicardipine and sodium nitroprusside, but interestingly a vasoconstrictor like epinephrine may also have a role. Glycoprotein IIb/IIIa platelet receptors antagonist have shown a powerful de-thrombotic effect, and the intracoronary administration appears to be particularly promising. We review the pathogenesis of a reduced epicardial flow during PCI and focus on those drugs that have been studied for the treatment of no reflow. Although no double blind, randomized trial has been conducted to assess any of these agents, or to determine the appropriate dosage, we try to identify some useful conclusions from the published evidence.

Flecainide overdose--support using an intra-aortic balloon pump.

BackgroundFlecainide is an antiarrhythmic agent which is being used increasingly for the management of super-ventricular arrhythmias. Overdose with flecainide is frequently fatal with mortality reported as high as 22% due to arrhythmias, myocardial depression and conduction defects leading to electro-mechanical dissociation and asytole. Supportive measures are often required during the case and previously have included inotropes, extracorporeal membrane oxygenation and cardiopulmonary bypass.Case presentationA 47 year old lady presented to the emergency department with a four hour history of severe central chest pain. Her ECG showed atrial fibrillation and broad QRS complexes with a sine wave appearance. She had a past history of paroxysmal atrial fibrillation and significant psychiatric history. Following thrombolysis for a presumed myocardial infarction she developed cardiogenic shock with severely impaired left ventricular function. An intra-aortic balloon pump was inserted and coronary angiography demonstrated normal coronary arteries. With inotropic support she improved over 48 hours, with both her QRS duration and left ventricular function returning to normal. Biochemical testing following her discharge demonstrated significantly elevated levels of flecainide.ConclusionThe use of an intra-aortic balloon pump is a useful supportive measure during the acute phase of flecainide overdose associated with severe myocardial depression.

Echocardiographic assessment and percutaneous closure of multiple atrial septal defects.

Atrial septal defect closure is now routinely performed using a percutaneous approach under echocardiographic guidance. Centrally located, secundum defects are ideal for device closure but there is considerable morphological variation in size and location of the defects. A small proportion of atrial septal defects may have multiple fenestrations and these are often considered unsuitable for device closure. We report three cases of multiple atrial septal defects successfully closed with two Amplatzer septal occluders.

Changes in Intrathoracic Impedance from a Pneumothorax: Insights from an Implanted Monitoring System

The measurement of transthoracic impedance is now possible using new implantable cardioverter‐defibrillators. This can be used to monitor fall in impedance associated with increasing pulmonary oedema. We describe a case of a large rapid increase of impedance and dyspnoea related to a pneumothorax.

Current indications for contrast echocardiography imaging.

UNLABELLED The assessment of regional ventricular function is dependent on good endocardial definition. Suboptimal images can be converted to diagnostic recordings in the majority of patients by contrast agents, which have become an indispensable aid in rest and stress echocardiography. In particular for stress echocardiography image quality is essential and contrast administration is of great importance. However this diagnostic procedure must be performed following the indications which reflect the risks of the procedure and consider the benefits of an accurate diagnosis on further patient management. The contraindications recently introduced in the use of the echo-contrast agent SonoVue for acute cardiac patients reflect the same contraindications which have been applied in stress echocardiography for several years. Clinical trials and post-marketing surveillance have demonstrated that this approach is safe with no fatalities reported. For all ultrasound contrast media, side effects have been reported but they are usually mild. However, rare allergic and potentially life threatening reactions may occur and the investigators have to be prepared for such an event with appropriate drugs stored in the echo department. In a recent retrospective analysis in 751 consecutive stress echocardiograms the use of contrast during dobutamine stress echocardiography was not associated with an increased risk of side effects. The incidence of side effects was very low and different in patients receiving Optison, SonoVue or without contrast agent. CONCLUSION Ultrasound contrast agents are licensed for improvement of endocardial border definition. Data from clinical trials and wide clinical experience indicate an excellent risk/benefit ratio if the current contraindications are applied.

Non-Pharmacological Methods of Maintaining Sinus Rhythm

To the Editor: The Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) investigators recently presented their analysis of the relationship between cardiac rhythm, treatment, and survival from the original AFFIRM study.1 The investigators conclude that the use of warfarin and the presence of sinus rhythm were important determinants of survival. The use of antiarrhythmic drug therapy to maintain sinus rhythm did not appear to improve survival, perhaps indicating that the mortality benefit from sinus rhythm was offset by the hazards of drug therapy. Though these data are retrospective and nonrandomized, the article supports epidemiological evidence that atrial fibrillation is an independent risk factor for mortality.2 After the publication of the rate versus rhythm data, changes in the management of atrial fibrillation have been reported.3 Patients that may previously have undergone cardioversion are now being maintained …

Cardiac papillary fibroelastoma presenting with recurrent ventricular tachycardia.

A 72‐year‐old man presented with multiple episodes of pulseless ventricular tachycardia, 10 days following an ST‐segment elevation myocardial infarction. He had a 6‐year cardiovascular history that included four neurological events and two myocardial infarctions. Transesophageal echocardiography revealed two mobile masses on the aortic valve. A transaortic surgical approach was successful in removing both masses. Histology confirmed papillary fibroelastoma. The patient subsequently received an implantable cardioverter defibrillator.

Contrast echocardiography for left ventricular opacification.

Echocardiography has been criticised of having only moderate reproducibility and of having a low sensitivity of changes in left ventricular ejection fraction (LVEF). Inadequate endocardial visualisation during echocardiography occurs in up to 20% of cases. Although image quality has been improved with the introduction of harmonic imaging,1,2 there are still a number of studies remaining of inadequate quality, and it is here that the use of contrast agents comes into its own.3 A number of studies have now been performed looking at the effect of contrast on assessment of cardiac regional and global function. This paper reviews the current and future clinical use of ultrasound contrast agents for assessment of left ventricular function. The first licensed contrast agent in the UK was Levovist (Schering, Germany) and has now been followed by Optison (Amersham, UK) and Sonovue (Bracco, Italy) which are licensed for left ventricular opacification. Although infusions are preferential for assessment of myocardial perfusion, bolus injections of agents may be satisfactory for left ventricular opacification in many cases. In tandem with the development of contrast agents have been advances in imaging modalities. The first contrast specific modalities were harmonic imaging and harmonic power Doppler, which both use a relatively high transmit power leading to bubble destruction. Optimal imaging therefore requires triggered imaging. Second harmonic imaging enhances contrast effect compared to fundamental imaging and has been used for border definition using real-time imaging.4 However, it also leads to bubble destruction and artefacts. Latest developments such as power modulation and power pulse inversion, which are low power techniques and non-destructive, allow for real-time imaging without the limitations of harmonic imaging and with less contrast. As tissue returns are not displayed, unlike with …