Monday, March 21, 2011

Septic Shock due to Implantable Cardiac Defibrillator Related Infection

Citation : David Palmer, Aleem Khand.Septic Shock due to Implantable Cardiac Defibrillator Related Infection .JAFIB.2011 February;Volume 2 Issue(4): 888-890.

Infection is an important complication of cardiac device implantation. We report the case of a 61 year old patient presenting with septic shock caused by cardiac device infection (CDI) three-weeks after device implantation. At initial presentation, there was an absence of both localising signs and echocardiographic evidence of CDI. Later, Staphylococcus aureus was cultured from blood and the pre-pectoral pocket. 48 hours after admission the device and leads were explanted in theatre by simple traction. Despite appropriate antibiotics and full supportive care (including haemofiltration, ventilation and inotropic support), the patient died on day six. Cardiac device infection may present with septic shock in the absence of localising features. A high index of suspicion is required, particularly for early CDI.

Role of Remote Navigation Systems in AF Ablation

Citation : Boris Schmidt, Britta Schulte-Hahn, Bernd Nowak, Verena Windhorst, Kyoung Ryul Julian Chun.Role of Remote Navigation Systems in AF Ablation .JAFIB.2011 February;Volume 2 Issue(4): 881-887.
During the past decade atrial fibrillation (AF) ablation has developed from being an experimental treatment option to an evidence based therapy implemented in current guidelines. Irrigated radiofrequency current guided ablations remain the golden standard of pulmonary vein isolation (PVI) procedures. Although practiced more frequently, it remains a demanding procedure requiring skilful operators. Novel technologies such as balloon based catheters or remote navigation (RN) systems have been developed to overcome the pitfalls of manual ablation procedures.

The Cost of Thromboembolic Events and their Prevention among Patients with Atrial Fibrillation

Citation : Thomas Davidson, Magnus Husberg, Magnus Janzon, Lars-Ake Levin. The Cost of Thromboembolic Events and their Prevention among Patients with Atrial Fibrillation .JAFIB.2011 February;Volume 2 Issue(4): 870-880.

Aim: Atrial fibrillation (AF) is the most common type of cardiac arrhythmia. People with AF have a significantly increased risk of thromboembolic events, including stroke, and the main treatment is therefore aimed at preventing thromboembolic events via anticoagulation with warfarin or acetylsalicylic acid. However, the development of new anticoagulation treatments has prompted a need to know the current cost of AF-related thromboembolic events, for future cost-effectiveness comparisons with the existing treatments. In this study, we estimated the cost of thromboembolic events and their prevention among Swedish AF patients in 2010.

Methods: The relevant costs were identified, quantified, and valued. The complications included were ischaemic and haemorrhagic stroke, gastrointestinal bleeding, and other types of major bleeding caused by AF. Treatments intended to lower the risk of ischaemic stroke were also included. A societal perspective was used, including productivity loss due to morbidity. Patients with a CHADS2 score of 1 or higher were included.

Results: Among the 9 340 682 inhabitants of Sweden, there are 118 000 patients with AF and at least one more risk factor for stroke, comprising 1.26% of the population. Of these patients, 43.3% are treated with warfarin, 28.3% use acetylsalicylic acid, and 28.3% are assumed to have no anticoagulation treatment. The cost of AF-related complications and its prevention in Sweden was estimated at €437 million for 2010, corresponding to €3 712 per AF patient per year. The highest cost was caused by stroke, and the second highest by the cost of monitoring the warfarin treatment. As the prevalence of AF is expected to increase in the future, AF-related costs are also expected to rise.

Conclusion: Thromboembolic events cause high costs. New, easily-administered treatments that could reduce the risk of stroke have the potential to be cost-effective.

Cardiac Image Registration: Rotational Error Correction and Gated Stabilization for Cardiac Motion

Citation : Jasbir Sra.Cardiac Image Registration: Rotational Error Correction and Gated Stabilization for Cardiac Motion .JAFIB.2011 February;Volume 2 Issue(4): 856-869.

Background: Dynamic motion of the heart due to cardiac and respiratory cycles, and rotation from varying patient positions between imaging modalities, can cause errors during cardiac image registration. This study used phantom, patient and animal models to assess and correct these errors.

Methods and Results: Rotational errors were identified and corrected using different phantom orientations. ECG-gated fluoro images were aligned with similarly gated CT images in 9 patients, and accuracy assessed during atrial fibrillation (AF) and sinus rhythm. A tracking algorithm corrected errors due to respiration, where 4 independent observers compared 25 respiration sequences to an automated method. Following correction of these errors, target registration error was assessed. At 20 mm and 30 mm from the phantom model\’s center point with an in-plane rotation of 8 degrees, measured error was 2.94 mm and 5.60 mm, respectively, and the main error identified. A priori method accurately predicted ECG location in only 38% (p=0.0003) of 313 R-R intervals in AF. A posteriori method accurately gated the ECG during AF and sinus rhythm in 97% and 98% of 375 beats evaluated, respectively (p=NS). Tracking algorithm for ECG-gated motion compensation was identified as good or fair 96% of the time, with no difference between observers and automated method (chi-square=25; p=NS). Target registration error in phantom and animal models was 1.75±1.03 mm and 0 to 0.5 mm, respectively.

Conclusions: Errors during cardiac image registration can be identified and corrected. Cardiac image stabilization can be achieved using ECG gating and respiration.