Cardiac safety profile for random complex waveforms (2017)

Type of publication:
Journal article

Author(s):
Pratt H, Andrews C, Panescu D, *Lake B.

Citation:
39th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), Seogwipo, 2017, pp. 3712-3718.

Abstract:
INTRODUCTION:
A rigorous method for assessing the Ventricular Fibrillation (VF) risk of a Random Complex Waveform (RCW) has not been previously available. Real-life hazardous events motivated us to develop such method. An RCW is observable and recordable. It consists of multiple different components randomly added one to the other. Assessment for VF risk exists for non-random waveforms, particularly VF thresholds for 50/60 Hz alternating currents, but not for RCWs.
METHODS:
We developed a method which considers exposure to a segment of an RCW. It transforms complex segment exposure to values which can be compared with AC root-mean-square (rms) magnitude/duration curves, for determination of VF risk. Human contact could occur for any given time duration within the segment. The current of most risk is the greatest found for all possible instances of that duration. This is termed the “Probable Current” (PC) for that duration. All possible exposure durations in the waveform segment are considered, giving a set of PCs, thus allowing the plotting of a PC curve. The PC set is compared with a criterion for VF risk, termed the Justified Current (JC) curve.
RESULTS:
The theory is presented. Demonstrations and examples are given. Code is shown for generating the PC curve.
CONCLUSION:
VF risk can be found for an RCW using the rigorous algorithm presented.
SIGNIFICANCE:
The VF for RCWs has not been considered previously. A rigorous statement of a method for VF risk assessment allows extension from regular waveforms to RCWs.

Predicting and measuring fluid responsiveness with echocardiography (2016)

Type of publication:
Journal article

Author(s):
*Miller, Ashley, Mandeville, Justin

Citation:
Echo research and practice, June 2016, vol. 3, no. 2, p. G1

Abstract:
Echocardiography is ideally suited to guide fluid resuscitation in critically ill patients. It can be used to assess fluid responsiveness by looking at the left ventricle, aortic outflow, inferior vena cava and right ventricle. Static measurements and dynamic variables based on heart-lung interactions all combine to predict and measure fluid responsiveness and assess response to intravenous fluid resuscitation. Thorough knowledge of these variables, the physiology behind them and the pitfalls in their use allows the echocardiographer to confidently assess these patients and in combination with clinical judgement manage them appropriately.

Link to full text: http://www.echorespract.com/content/3/2/G1.abstract

Chest pain with raised troponin, ECG changes but normal coronary arteries (2014)

Type of publication:
Journal article

Author(s):
*Amjad A,  *Ali A, *Bashir A,  *Ali M,  *Azam MN

Citation:
BMJ Case Reports, 2014, vol./is. 2014/, 1757-790X (2014)

Abstract:
A 65-year-old woman presented to A&E department, with acute onset central chest pain and dyspnoea. ECG showed dynamic T wave changes while 12 h troponin was elevated. A diagnosis of acute coronary syndrome was made and she underwent an inpatient coronary angiogram. Although her coronary arteries were normal, symptoms persisted and D-dimers were found to be elevated. This led to a CT pulmonary angiogram, which ruled out pulmonary embolism, but uncovered a large ascending aortic aneurysm with a contained leak. She was immediately transferred to regional cardiothoracic unit for urgent surgical intervention. This case report illustrates the importance of a good clinical history, physical examination and timely investigations. It also emphasises that not all chest pain events with elevated troponin level are due to acute coronary syndrome and that alternative diagnoses should still be considered.

Link to more details:

Link to full-text: http://casereports.bmj.com/content/2014/bcr-2013-201975.abstract

 

Asymptomatic coronary artery spasm with acute pathological ST elevation on routine ECG: is it common? (2014)

Type of publication:
Journal article

Author(s):
Mohammed I, *Zaatari MS, Tyrogalas N, Khalid MI

Citation:
BMJ Case Reports, 2014, vol./is. 2014/, 1757-790X (2014)

Abstract:
Asymptomatic spontaneous coronary artery spasm is rare and there are no case reports in literature presenting with acute ST elevation on routine ECG. We present the case of a 68-year-old Caucasian man who presented to a primary care physician for a routine ECG as part of hypertension follow-up. ECG revealed ST elevation in inferior leads II, III and aVF with reciprocal ST depression in leads I, aVL and also ST depression in anterior leads V1, V2 and V3 suggesting ongoing inferoposterior ST elevation myocardial infarction. The patient was completely well, stable and asymptomatic and he was rushed immediately to the coronary care unit via emergency ambulance. The patient was subjected to a battery of urgent investigations which were all normal. Also an urgent coronary angiogram was undertaken which showed completely normal coronary anatomy. 2014 BMJ Publishing Group Ltd.

Link to full-text: http://casereports.bmj.com/content/2014/bcr-2013-202586.abstract