ABSTRACT
Cardiomyopathies (CMPs) are a group of often inherited diseases characterised by abnormalities and associated dysfunction of heart muscle. In the past decade, cardiovascular magnetic resonance (CMR) has emerged as a powerful tool in their assessment, providing data that are complementary to other aspects of clinical evaluation. Key advantages of CMR are three-dimensional visualisation of the heart and its relationship to thoracic structures; gold-standard quantification of cardiac volumes and function, which can safely be repeated over time (no ionising radiation is involved); and tissue characterisation to detect focal scar and fatty infiltration. This paper reviews the role of CMR in the clinical assessment of patients with CMPs.
Subject(s)
Cardiomyopathies/diagnosis , Magnetic Resonance Imaging/methods , Arrhythmogenic Right Ventricular Dysplasia/diagnosis , Cardiomyopathy, Dilated/diagnosis , Cardiomyopathy, Restrictive/diagnosis , Contrast Media , Coronary Vessels/physiopathology , Humans , Ischemia/diagnosis , Takotsubo Cardiomyopathy/diagnosis , Ventricular Function, Left/physiologyABSTRACT
Transthoracic impedance (TTI) is an important determinant of success in defibrillation. Low TTI increases transmyocardial current and therefore increases the chance of depolarising a critical mass of myocardium. A major component of TTI occurs at the paddle-skin interface and is minimised by pressure applied to the defibrillation paddles. The International Liaison Committee on Resuscitation (ILCOR) 2000 guidelines recommend that 'firm force' should be applied to both paddles, whereas previous European Resuscitation Council (ERC) 1992 guidelines were more precise, recommending that 12 kg of force should to be applied. We assessed whether defibrillator operators are capable of achieving 12 kg paddle force. Fifty advanced life support-trained doctors and nurses attempted to achieve 12 kg paddle force while simulating defibrillation on a resuscitation doll. The median value of the maximum pressures obtainable was 10.1 (max 16.0; min 5.0) kg force. Only 14% could achieve > or =12 kg force on both paddles for defibrillation. Men achieved more force than women (10.7 vs. 8.1 kg force; P<0.01), and there was a correlation between maximum force achieved and operator height (r2=0.27) and dominant hand-grip strength (r2=0.34). The ERC recommendation of 12 kg paddle force is not achievable by the majority of defibrillator operators.
