Tracings 4.1

A 62 year-old man was conveyed to the  ED in Police Department custody complaining of pressure-like chest pain. The patient relates that his chest pain came on coincidentally with the stress brought on by his arrest approximately 24 hours prior. It has been “off and on” since then. The police had taken the patient to an outside hospital on the day prior to this ED visit for chest pain. The patient reports that he was told that he had “some type of heart block” and that they wanted to do a cardiac catheterization but he refused and left AMA.

The patient relates a history of chest pain dating back several years but he has never had a heart attack. The pain occurs twice a week, is precipitated by stress or exercise, does not radiate, is accompanied by “a little” shortness of breath and generally resolves after 20 minutes.  He relates that he “miserably failed” a stress test one year prior, but did not want to undergo a cardiac catheterization at the time.

PMH: Type 2 diabetes, hyperlipidemia.  Medications are glipizide 10 mg twice a day, nitroglycerin sublingually when necessary, simvastatin 20 mg daily, aspirin 81 mg daily. He denies alcohol, tobacco, and illicit drug use.

On exam, BP is 122/76, R 18, P 78 and irregular, T 36.0. there are no other significant findings.

This ECG is obtained. What is your interpretation?

The ECG reflects normal sinus rhythm at a rate of 75 bpm (P waves identified with arrows). Some of the P waves that fall on T waves look slightly more peaked than the others but this is an interaction with the T wave, not a second atrial focus. This fact is confirmed by the observation that the P waves all march out.

The long PRs and widely varying PR intervals might make one tempted initially to interpret the tracing as 3rd degree AV block.

However, a basic ECG principle is: be suspicious of complete HB as a diagnosis when the QRS rhythm is irregular. Why? Because you should expect an escape AV nodal or ventricular rhythm to be regular. And this rhythm is pretty irregular.

So….another look reveals that there are repeating PR intervals of differing durations, each identified on the tracing above as “A”, “B”, and “C”. This rules out A-V dissociation…and eliminates complete heart block as a diagnosis.

The cycles of increasing P-R intervals with some blocked  P waves (marked with “X”) are diagnostic of Mobitz Type I (Wenckebach) second degree heart block. One of the blocked beats (marked with a question mark) falls on a QRS complex and is therefore not visible.

There is generally 3:2 conduction present, that is, for each 3 P waves, 2 are conducted to the ventricles and produce QRS complexes. (Or you could also say 3:1 block; for each 3 P waves, 1 is blocked.) The exception is the third complete group of beats, for which there is only an “A” PR interval before a P wave is blocked, reflecting 2:1 conduction (or, if you prefer, block).

When second degree heart block presents with consistent 2:1 conduction, it is impossible to tell whether there is Type I or Type II second degree block. However, when there is 2:1 block with concurrent evidence of Wenckebach conduction, as we have here, we can assume that Wenckebach conduction  prevails.

Finally, there is also first degree heart block, as the shortest P-R interval measures 0.44 sec. Indeed, if this were not present, the diagnosis of Mobitz I would be considerably less problematic.

Case follow up: the patient ruled out for acute MI with 2 negative troponins. He was offered cardiac catheterization and/or further cardiology consultation but signed out against medical advice.

Tracings is a learning module involving actual cases of patients and their ECGs that present to the Emergency Department.  Topics are derived from the EM Model for Resident Education. Cases are prepard by Dr. William Berk.

Tracings Vol 3.2 Answer

Case

A 42-year-old man is conveyed to the ED via private vehicle with a 1-week history shortness of breath and bilateral leg swelling. Past medical history is negative; he takes no medications. He injects heroin, last 2 hours prior to arrival, and smokes tobacco.

On exam, blood pressure is 112/73 mm Hg, pulse 125 bpm, respirations 20, temperature 35.9. Chest is clear and heart sounds normal. Mild symmetrical pitting edema is noted in both legs up to the knees. Pulses are intact.

Pulse oximetry registers an oxygen saturation of 78% on 5 liters of oxygen per minute via nasal cannulae.

The attached ECG and CxR were obtained. (Click on image to enlarge)

ECG Vol 3.2CXR Vol 3.2

Questions:

1. Interpret the ECG?

2. List 3 of the most likely diagnoses?

3. What is the most appropriate management for this patient?

Answer

The Chest x-ray reflects cardiomegaly. Pulmonary arteries are enlarged and pulmonary vasculature is prominent without cephalization.

ECG shows normal sinus rhythm at a rate of 68bpm. There is low voltage in the QRS of the limb leads (<5 mm in each lead). Right axis deviation is present and that along with a nearly equipotentialed QRS in V1 suggests RV strain or hypertrophy.

Low voltage on the ECG combined with cardiomegaly on chest x-ray should strongly suggest pericardial effusion. The presence of right heart strain and right axis deviation on ECG combined with a low pulse ox and no chest x-ray finding that can explain a large A-a gradient should suggest pulmonary embolism.

Bedside ultrasound confirmed pericardial fluid. CT with contrast showed bilateral segmental PE’s, pericardial effusion, and a large heterogeneous posterior mediastinal mass with areas of necrosis, possibly an esophageal leiomyona.

Heparin and antibiotics were started. The patient was admitted to the MICU. Troponins were 1.13 and 1.24. On the 2nd hospital day, leg doppler ultrasound showed a right common femoral vein non-occlusive thrombus. Blood cultures were negative.

On the 3rd hospital day, the patient signed out AMA. Three months later he has no further medical records at the institution the initially carded for him.

Tracings is a learning module involving actual cases of patients and their ECGs that present to the Emergency Department.  Topics chosesn are dervied from the EM Model for Resident Education. Cases are prepared by Dr. William Berk.

Tracings Vol 3.2

Case

A 42-year-old man is conveyed to the ED via private vehicle with a 1-week history shortness of breath and bilateral leg swelling. Past medical history is negative; he takes no medications. He injects heroin, last 2 hours prior to arrival, and smokes tobacco.

On exam, blood pressure is 112/73 mm Hg, pulse 125 bpm, respirations 20, temperature 35.9. Chest is clear and heart sounds normal. Mild symmetrical pitting edema is noted in both legs up to the knees. Pulses are intact.

Pulse oximetry registers an oxygen saturation of 78% on 5 liters of oxygen per minute via nasal cannulae.

The attached ECG and CxR were obtained. (Click on image to enlarge)

ECG Vol 3.2CXR Vol 3.2

Questions:

1. Interpret the ECG?

2. List 3 of the most likely diagnoses?

3. What is the most appropriate management for this patient?

Please post your answer in the “reply box” or click on the “comments” link  You will not see your answer post until next week when all of the submitted answers will be posted.  Good luck!

Tracings is a learning module involving actual cases of patients and their ECGs that present to the Emergency Department.  Topics are derived from the EM Model for Resident Education. Cases are prepared by Dr. William Berk.

Tracings Vol 3.1 Answer

HPI

A 15 y.o. girl was transported by EMS to the ED. She had just experienced her second syncopal episode in 8 days. This morning while in the bathroom at her family’s home getting ready for school, she felt nauseous and then passed out. When she awoke, EMS was on the scene. She had had a previous syncopal episode 8 days prior while at school. On that occasion she had gone into the girls’ bathroom and then woke up lying on the floor. “Possible” seizure activity was observed. Since that time she has had a throbbing headache involving the entire head. Neither episode had associated chest pain, shortness of breath, faintness or focal neurologic symptoms. Her last menstrual period had been 3 weeks prior.

Past medical history was significant for a congenital single kidney and appendectomy. She was taking no medications. There was no history of drug, alcohol or tobacco use.

Physical Exam

On exam the patient appeared alert and generally well. BP was 116/66, pulse 73, respirations 20, and temperature 36.5C. General, cardiopulmonary, neurologic and extremity exams were all normal. Pulse oximetry registered a 100% saturation on room air.

Review of the EMR revealed that a brain CT performed during the ED visit 8 days prior had been normal. UDS and SDS had both been negative. The patient had been discharged from the ED and referred to her primary care physician. He had obtained a neurology consult which found no abnormalities and an EEG which was normal.

During the present visit, a 12-lead ECG was normal and initial laboratory evaluation was unremarkable. After conferring with the patient’s physician, a decision was made to obtain an echocardiogram.

While the patient was awaiting this study, the cardiac monitor alarm activated and a rhythm strip was recorded. The patient remained asymptomatic and the abnormality which had triggered the alarm resolved before any action could be contemplated.

Repeat VS and a directed exam were unremarkable.

Questions

1.  What rhythm does this strip reflect?

2.  What should be done next?

Case ECG ACase ECG B

Discussion

The rhythm strip reveals what appears to be a wide-complex QRS rhythm with a rate of around 215 bpm. On the surface this seems highly suspicious for ventricular tachycardia. Another possibility might be a supraventricular re-entrant or atrial tachycardia with aberrant conduction.

However, there are narrow QRS complexes running through and apparently dissociated from the wide-complex QRS rhythm (see arrows) and at a rate that is identical to the sinus rhythm at the beginning of the strip.

What’s going on?

Since you can’t have simultaneous and concurrent ventricular depolarizations of the ventricle triggered by both the sinus impulse and an ectopic ventciular pacemaker (note that some of the narrow beats land on the wider deflections and some land in between), the only explanation is that  the wide-complex QRS rhythm is artifact, most likely electrical in origin.

In this case, a consulting cardiologist determined that the rhythm was artifact. Further workup failed to reveal a cause for this patient’s recurrent syncope.

Lesson: look for this phenomenon when apparent wide complex rhythms are recorded by cardiac monitors, especially when the patient remains asymptomatic (although a patient can certainly remain asymptomatic during runs of VT).

Tracings is a learning module involving actual cases of patients and their ECGs that present to the Emergency Department.  Topics chosesn are dervied from the EM Model for Resident Education. Cases are prepared by Dr. William Berk.

Tracings Vol 3.1

HPI

A 15 y.o. girl was transported by EMS to the ED. She had just experienced her second syncopal episode in 8 days. This morning while in the bathroom at her family’s home getting ready for school, she felt nauseous and then passed out. When she awoke, EMS was on the scene. She had had a previous syncopal episode 8 days prior while at school. On that occasion she had gone into the girls’ bathroom and then woke up lying on the floor. “Possible” seizure activity was observed. Since that time she has had a throbbing headache involving the entire head. Neither episode had associated chest pain, shortness of breath, faintness or focal neurologic symptoms. Her last menstrual period had been 3 weeks prior.

Past medical history was significant for a congenital single kidney and appendectomy. She was taking no medications. There was no history of drug, alcohol or tobacco use.

Physical Exam

On exam the patient appeared alert and generally well. BP was 116/66, pulse 73, respirations 20, and temperature 36.5C. General, cardiopulmonary, neurologic and extremity exams were all normal. Pulse oximetry registered a 100% saturation on room air.

Review of the EMR revealed that a brain CT performed during the ED visit 8 days prior had been normal. UDS and SDS had both been negative. The patient had been discharged from the ED and referred to her primary care physician. He had obtained a neurology consult which found no abnormalities and an EEG which was normal.

During the present visit, a 12-lead ECG was normal and initial laboratory evaluation was unremarkable. After conferring with the patient’s physician, a decision was made to obtain an echocardiogram.

While the patient was awaiting this study, the cardiac monitor alarm activated and a rhythm strip was recorded. The patient remained asymptomatic and the abnormality which had triggered the alarm resolved before any action could be contemplated.

Repeat VS and a directed exam were unremarkable.

Questions

1.  What rhythm does this strip reflect?

2.  What should be done next?

Case ECG ACase ECG B

Please post your answer in the “reply box” or click on the “comments” link  You will not see your answer post until next week when all of the submitted answers will be posted.  Good luck!

Tracings is a learning module involving actual cases of patients and their ECGs that present to the Emergency Department.  Topics are derived from the EM Model for Resident Education. Cases are prepared by Dr. William Berk.

Answer Tracings Vol 1.2

Winners

Allison Loynd          Marjan Siadat       Richard Gordon

David Mishkin         Brian Kern

Case

ecg2

ECG Interpertation

  • anterolateral wall STEMI
  • ST-elevation in leads I, AVL and precordial leads V2-V6.
  • Evolving Q waves are seen in several leads.

There is, in addition, complete heart block (CHB). The atrial rate is 125 bpm, while the ventricles are beating at 52 bpm. The arrows in ECG#2 show P waves (except the 8th P wave, which is buried in a QRS complex) marching through the QRS complexes.

Remember: you have AV dissociation but NOT CHB if the atria and ventricles are dissociated BUT the ventricular rate is FASTER than the atrial rate.

Discussion

CHB occurs in about 5% of STEMIs. When it occurs in association with anterior wall MI, the prognosis is grave with mortality as high as 70-80%. This apparently is not causally related to the CHB itself but reflects that large MIs, which have worse outcomes, are more likely to have associated CHB.

In this case the patient was taken rapidly from the ED to the cath lab, where the LAD was found to have a proximal ruptured plaque with thrombus resulting in a 99% stenosis. This was successfully stented. A large troponin leak peaked at >22.78.

Although complete heart block with STEMI is generally considered to be an indication for at last temporary pacemaker placement, in this case after stenting the heart block resolved and it was felt that the patient did not need a pacemaker.

Echocardiogram on the 2nd hospital day showed a small LV cavity with concentric hypertrophy, severe hypokinesis of the mid
to distal and anterior septal wall, and akinesis of the apex. Ejection Fraction was 35%.

The patient was discharged home on the 4th hospital day.

Tracings is a learning module involving actual cases of patients and their ECGs that present to the Emergency Department.  Topics chosesn are dervied from the EM Model for Resident Education. Cases are prepared by Dr. William Berk.

Tracings Vol 1.2

A 79-year-old Bangladeshi man arrived in the ED via private car.  He describes having chest pain for 4 hours that is worse on the left side than the right. He speaks no English and it is impossible to immediately obtain a more detailed recent history.  His past medical history includes Type 2 diabetes and a  “thyroid problem.” His medications include glipizide 5 mg once daily and levothyroxine 50 mcg once daily. On exam, his BP is 154/71 mm Hg, P 62 beats per minute, R 18 breaths per minute, and T 96.7. He is alert and as far as can be ascertained, oriented. There are no other significant exam findings.
A 12-lead ECG was obtained as seen below.

ecg1

Questions:

1.  What is your ECG interpretation?
2.  What is your disease differential diagnosis?
3.  What would you do?

Please post your answer in the “reply box” or click on the “comments” link  You will not see your answer post until next week when all of the submitted answers will be posted.  Good luck!

Tracings is a learning module involving actual cases of patients and their ECGs that present to the Emergency Department.  Topics are derived from the EM Model for Resident Education. Cases are prepard by Dr. William Berk.