Non Sustained VT: Making a Lasting Impression!

Putting on the Pressure

A 60 yo male presents to EMS with several hours of chest pressure and diaphoresis. A 12 lead ECG is obtained following a 10 beat run of non sustained ventricular tachycardia. Despite the EMT's excitement at "firing up the paddles," the paramedic administers 324 mg of aspirin and prepares for transport to the nearest facility capable of percutaneous coronary intervention. Your partner informs you that the monitor discerns the presence of a paced rhythm. The patient has no previous medical history.


12 LEAD ECG:

12 LEAD ECG Analysis:

A sinus rhythm is present and the rate is regular. Diffuse and concerning ST segment changes appear in this tracing. First, pathologic ST segment elevation occurs in leads V2, V3 and V4. Q waves also appear throughout the tracing. The monitor misinterprets the ischemic Q wave as a pacer spike. The QRS is narrow, so an interventricular conduction delay is less likely responsible for the "false pacer" call. Reciprocal changes appear in lead aVF. There is minimal J point depression in lead III and V6. The baseline is also irregular.


12 Lead ECG Interpretation: 

Sinus rhythm, anterior wall ST segment myocardial infarction.

Comments:

• It is difficult to discern the location of the anatomic lesion based upon this ECG. The large ST segment elevation in the precordial leads suggests involvement of the LAD. The findings of lateral wall ischemia could implicate the circumflex as well. 
• The run of VT was likely due to ventricular irritability. Remember that the most devastating complications of anterior wall ischemia are lethal dysrhythmia and cardiogenuc pulmonary edema 
• Pathologic Q waves generally follow a few rules: (1) larger than a third of the corresponding R wave or (2) measure in excess of 0.03 seconds. Q waves that accompany poor R wave progression are more likely to indicate ischemia. 

Simple STain on the Strain

Sometimes LVH isn't all that simple. The "strain" pattern has been discussed elsewhere on this and other blogs, but this is an example of an atypical, and concerning, ECG:

What's not (so) unusual: 
The ECG reveals a sinus rhythm. The downsloping ST segments and T wave inversions seen in the lateral leads and precordial leads may be expected in the setting of high left ventricular voltage. The pattern of LVH and ST/T wave changes is consistent with, "strain."

What's concerning: 
The ST segment elevation present in aVL and V1-V2 is NOT concave and almost horizontal. This type of ST segment change is consistent with ischemia. Furthermore, it appears in an anatomic distribution. ST segment changes in aVL and V1-V2 suggest anterior or anterior lateral ischemia. Though LifeNET measures the ST segment elevation at less than 2 mm, it is nevertheless cause for concern especially given a "typical" story or history consistent with an acute coronary syndrome.

Bottom line and interpretation:
Carefully evaluate ST segment deviation in all leads. Look for atypical elevation and an anatomic distribution of the ECG changes.
Sinus rhythm, ST segment depression and T wave inversion consistent with strain pattern. ST segment elevation in the anterior precordial leads and aVL suspicious for STEMI. 

Well, I didn't see anything in the rhythm strip...

Case Description


Medics respond to the report of a 66 yo male with nausea, chest pain, and chest pressure radiating to the left arm. The patient appears well. Chest discomfort started 2 hours prior to EMS arrival. The patient's vital signs are as follows: BP: 168/100, P: 72, R: 60/regular. Sp02: 96% on RA. Physical examination is unremarkable. The patient is loaded for transport, and the paramedics consider aspirin and nitrates. A 12 lead ECG is obtained


12 lead ECG

12 Lead ECG Interpretation and Discussion 

The rhytm is sinus in origin, and there does not appear to be any ectopic beats. ST segments are upright with the exception of expected T wave inversion in lead aVR. Careful scrutiny of the inferior leads reveals subtle ST segment elevation of approximately 1 mm. ST segments should be measured at the "J" point, and there is just about 1 mm / 1 box of elevation in the inferior leads. Further substantiating the findings of ischemia are the ST segment elevations present in leads V2-V5. The ST segments takes on an almost horizontal appearance in V5 and the R wave progression is preserved. Reciprocal change in the form of ST segment flattening and depression appears in leads I and aVL. When deciding if any one ECG represents ischemic patterns look for (1 ) anatomic distribution of abnormal findings and (2) reciprocal changes. This ECG features both of these findings. This patient was transported for urgent PCI; I do not have angiographic findings available. The ST elevation in the limb leads is not all that impressive. It is easy to imagine that placing this particular patient "on the monitor" would interfere with the recognition of concerning ST-T changes in the precordial leads. 

Closer look at ST segment ugliness

12 Lead Interpretation

Sinus rhythm, rate of 60, widespread ST segment elevation in the inferior and anterior-lateral leads concerning for acute ischemia.

Pearls

• If there is ANY suspicion for coronary ischemia or cardiac-related chest pain, perform a complete 12 lead
• The presence of recipocal change makes the diagnosis of ischemia more likely
• Territorial ST-T changes (anterior, lateral, inferior) are similarly concerning for ischemia

Thoughts on another acute process that might produce widespread, diffuse STE? 

Where is the Circulatory Road Block?

Case

An 81 y/o female with DM, HTN, and bilateral lower extremity amputations presents to EMS with chest pain and vomiting. VS: BP: 90/40, P: 80, R:16. Sp02: 95%. The patient is alert and oriented and in mild distress. An ECG is obtained. What is your interpretation ?

12 Lead ECG

ECG Interpretation 

A first degree AV block is present. Deep Q waves and ST elevations are present in the inferior leads III, and aVF. Additional ST segment elevations are present in the anterior precordial leads V3, V4, and V5. Reciprocal depression is present in leads I and aVL. A right bundle branch block is suggested by the positively deflected QRS and increased QRS duration seen in V1. This patient is experiencing a large STEMI given the presence of elevation in multiple territories. ST elevations suggest active injury and ischemia in the inferior and anterior leads. The relative hypotension may indciate cardiogenic shock. Cardiogenic shock complicates a significant percentage of anterior wall myocardial infarctions. Multi-territorial ST elevations indicates a poor prognosis.

Treatment Course 

Providers transmit the 12 lead ECG and alert the receiving facility of an ST elevation myocardial infarction. Aspirin is administered. The patient proceeds directly to the cath lab. The patient had severe, multi-vessel, obstructive coronary artery disease and unfortunately expired from decompensated cardiogenic shock

Key Points

• Remain vigilant for the presence of cardiogenic shock in the presence of anterior wall ischemia
• ST elevations in multiple geographic areas (inferior and anterior in this case) indicate severe disease
• Ventricular fibrillation can also accompany large anterior wall MIs
• Relative hypotension is extremely significant in patients who are accustomed to higher blood pressures. In this case, the patient's marginal blood pressure resulted from acutely decreased cardiac output. 

Anterior Wall Changes and Abnormal ECG, UNCONFIRMED!

A 60 yo male with a history of CAD, MI, and HTN presents with retrosternal chest discomfort. He is hemodynamically stable. The prehospital provider obtains a 12 lead ECG.

12 lead ECG interpretation: 

A sinus tachycardia is present, and there are plenty of abnormal ST segment changes to point out. First, there is minimal ST segment elevation in V1, V2, and V3 .The ST approaches 2 mm in V2. In addition, the ST segments have a non-concave, or worrisome, appearance in V4. There is T wave inversion in aVL and downsloping ST segments in lead I. Those ST segments resemble the pattern of "ventricular strain."

Sinus tachycardia, ST segment elevation in the anterior precordial leads, anterior and lateral T wave inversion consistent with ischemia.

12 lead ECG case discussion: 

The paramedic scrutinized the anterior ECG changes and declared a, "STEMI." Though the receiving facility determined that the initial prehospital ECG changes did not meet strict STEMI criteria, the paramedic was clearly advocating for the patient's best interest by electing to transport directly to a cardiac interventional center. Previous ECGs from the same patient reflected prior ST segment abnormalities, and the patient wasd admitted to the cardiology service for further testing. Minor, baseline ST segment elevations in precordial leads in addition to high left ventricular voltage can confound the diagnosis of STEMI. The presence of at least 2 mm of elevation plus the identification of reciprocal change (in the form of ST segment depression) makes the diagnosis of STEMI much more likely. Always remember that serial ECGs are extremely important when dealing with concerning or "borderline" presentations.

The History of Present (and Past) Illness

EMS responds to the home of a 69 yo male patient. The patient reports retrosternal chest pain x 3 hours. The patient has taken 2 of his own nitroglycerin without relief. The patient reports mild shortness of breath. He denies nausea or loss of consciousness. The  patient is slightly diaphoretic and states, "you know, this feels entirely similar to my previous MI's." The patient has a history of coronary artery disease, HTN, and placement of three metal stents.

Vital signs:
BP: 180/100
P: 90
R: 22

Sp02: 94%

12 Lead ECG:

12 Lead ECG Interpretation and Discussion:

There is a baseline sinus rhythm. The rate is approximately 80 beats per minute. There is ST segment elevation in lead I. In addition, ST segment elevation is present in leads V2-V4. There are no reciprocal changes in the inferior wall leads. There are non specific ST segment changes (flattening) present in leads V5-V6.  The QRS axis is difficult to determine but the slightly positive complex in lead aVF and the positive complex in lead I put the mean vector at about 0 degrees, or within the physiologically "normal" range. (17 degrees according to the all knowing interpretation software..)
Incidentally, the QRS is decreased in amplitude. Low voltage QRS is concerning in the setting of patients who present in extremis or with hypotension. Low voltages can indicate serious underlying conditions such as pericardial effusion and tamponade. The patient is hypertensive and a bit tachypneic (RR>18). Remain vigilant for the development of pulmonary edema.



The distribution of the ST segment elevation suggests an acute infarction of the heart's septal and anterior walls. Lead I STE may indicate some lateral involement as well. Patients with anterior wall STEMI are at risk for the development of dysrhythmia and congestive heart failure. The routine administration of morphine sulfate, contrary to many established protocols, has not been associated with improved patient outcome. Administer aspirin, nitroglycerin, and transport to a facility capable of percutaneous coronary intervention.

As mentioned in previous cases, ST segment elevation in leads aVR or even V1 may be predictive of a left main coronary artery occlusion. The anterior wall injury pattern, as seen in this ECG, may be due to acute occlusion of the left anterior descending artery or one of its branches. It is challenging to reliably identify the culprit lesion; anatomy is always better defined during the cardiac catheterizaton.

Final ECG Interpretation:
Sinus rhythm, rate of 90, anterior wall STEMI. Probable acute lateral wall ischemia  Low voltage QRS.  

Ante up!

CASE PRESENTATION

The patient is a 40 yo male reporting a 9/10 pressure in the center of his chest. The patient appears pale and diaphoretic.

Family history is significant for early coronary artery disease. The patient felt well prior to experiencing the "pressure in his chest."

What does the 12 lead ECG show ?
Where is this patient's occlusion ?

12 LEAD ECG INTERPRETATION

Sinus rhtyhm, rate of 60, anterior lateral STEMI

A baseline sinus rhythm is present. ST segment elevation is seen in leads V1-V5. Leads I and aVL also reveal significant > 1 mm elevation of the ST segment. Reciprocal changes in the form of ST segment depression are best visualized in the inferior limb leads III and aVF.

The distribution of ST elevation across most of the precordium suggests obstruction of the left main or left anterior descending artery. The LAD supplies blood to the left ventricule. Diagnonal branches of the left coronary artery supply the lateral wall of the left ventricle. Occlusion of a diagnoal branch corresponds to ST elevation in leads I and aVL.

EMS PEARLS
Complications related to a massive anterior myocardial infarction include:
1. Dysrhythmia (VT/VF)
2. Congestive heart failure

Congestive heart failure may occur when approximately 40% of the LV muscle mass is lost to infarction.