Filed under: Pulseless Electrical Activity (PEA)
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Patient: n/a
ECG discussion: The top strip starts with sinus rhythm at ca. 75 bpm. Note that this generates a mean arterial pressure (MAP) of only 18 mmHg. A marked horizontal ST depression is also seen, which correlates with the pleth signal showing SpO2 of 74%. After 8 beats, there is no visible sinus activity any longer. No junctional escape rhythm is initiated, which indicates that the atrioventricular junction is also poorly perfused and suffering. The following beats are wide and slow, at only 35 bpm. Even though they resemble a ventricular/Purkinje escape rhythm by their morphology and regularity, this electrical activity is not able to create myocardial contraction. In the second strip, MAP is 13 and flatlined. This is explained electrophysiologically as electromechanical dissociation (EMD), which is similar to the term pulseless electrical activity (PEA).
The final (bottom) strip shows how the electrical activity ceases. Although mechanical asystole probably has happened already (hard to say without echocardiography), electric asystole has now also occured. Note that at the end of the strip the pleth wave is also flat.
September 8, 2009
The prehospital ECG obtained in the patient's home, the moment before cardiac arrest. Click image for full scale version (will open in a new window)
Patient: Male 90 y/o. Previous medical history unknown. Sudden onset of chest pain and severe dyspnea in his home. EMS responds quickly and this ECG is obtained in home. The ECG shows an AV junctional rhythm in the bradycardic range. The patient is awake but in severe pain. During transport to the hospital, the patient goes into full cardiac arrest. ACLS is started and is continued during transport to the ER. On arrival in the ER, ACLS continues. The patient is pulseless, with agonal respiration. After a total of one hour of ACLS without result, the resuscitation attempt is called off.
These strips are obtained in the ER from the defibrillator pads and show the progression from Pulseless Electrical Activity (PEA) into a flatline on the monitor. Note: PEA is also sometimes referred to as Electromechanical Dissociation (EMD), which is perhaps a more precise description of the electrophysiologic phenomenon that occurs. EMD is simply the term for when electrical activity occurs in the myocardium, but fails in depolarizing the cells and causing contraction of the heart muscle. This means that PEA/EMD is an agonal rhythm, and that PEA per definition is equal to asystole. However, when people say asystole, they usually refer to a flat line on the monitor/ECG. The next strips show the progression from PEA/EMD into a flat line.
First strip show chest compressions at a rate of ca. 140 bpm, followed by a rhythm check that displays an agonal rhythm/PEA. Compressions then start again. The next strips are recorded from the defibrillator during the next minutes and show the gradual morphologic progression from PEA into what is commonly referred to as flatline.
June 1, 2009
ECG limb leads tracings from a middle-aged man with who went into cardiac arrest in his home. The patient was resuscitatated and transported to the hospital, but cardiac arrest occured during catheterization. Angiography showed 100 % occlusion of the distal LMCA and proximal LAD. Despite PCI and several hours of ACLS, success was not achieved.
These tracings show EMD/PEA, as the patient was pulseless at the time. Notice how the PEA slowes down, evolving more and more into a flatline ECG.
December 8, 2008
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Patient: Elderly male person with no known cardiac disorders. Presented in the ER with pressing, retrosternal chestpain, non-radiating. He is fatigued, with pale skin and mild diaphoresis. No dyspnoea or cyanosis. He is normotensive. Initial ECG is completely normal. After three hours, sudden and unexpected cardiac arrest occurs. Eccocardiogram shows cardiac tamponade, probably due to rupture of proximal aorta. Resuscitation is unsuccessful. This ECG recording was made when resuscitation ended, one hour after cardiac arrest occured.
ECG description: The ECG shows a broad complexed and slow rhythm. The patient is apneic and pulseless, and yet there appears to be electrical activity in the heart. There has occured an electromechanical dissociation in the heart, as the electrical impulses do not lead to contractions. Cardiac output is none. This is called Pulseless Electrical Activity.
December 3, 2008