Let’s look at a case study that demonstrates the potential danger associated with right ventricular infarction.
EMS is called to the residence of a 68 year old female with chest pain.
On arrival, the patient is anxious, cool, pale, and diaphoretic.
Vital signs are assessed.
- HR: 68
- RR: 20
- NIBP: 105/55
- SpO2 95% on RA
A 12 lead ECG is captured showing acute inferior STEMI.
The other issue to consider is how you’re going to manage the patient.
The paramedic in charge of the call wisely suspected the possibility of right ventricular involvement and decided to capture another 12 lead ECG using modified lead V4R.
Basically, this is lead V4 moved over to the right side of the chest (hence the addition of the letter ‘R’ which stands for ‘right’).
Does this mean that every patient with right ventricular involvement will develop the hypotensive syndrome? No. But it means the patient is at risk and drugs like nitroglycerin and morphine should be used with caution!
Here is the 12 lead ECG with lead V4 in the position of V4R.
Even if there wasn’t quite 1 mm of ST segment elevation in this lead, because the QRS complex is so small, you’d want to consider the amount of ST segment elevation relative to the size of the QRS complex (thanks for this tip Dr. Smith).
This is the inverse of the rule for LBBB (and LVH) where the deeper the S wave, the higher the ST segment.
So we have a patient with acute inferior STEMI with right ventricular involvement.
Place the patient on oxygen, start an IV, and give the patient a fluid bolus!
These patients can handle a lot of fluid, and it helps maintain their pressure, especially if you’re even thinking about a trial of nitroglycerin!
The paramedic on this call gave the patients a bolus of 500 ml 0.9% NS which brought the patient’s pressure up to 124/68.
A single dose of SL NTG brought the patient’s pressure down to 90/48.
Can you imagine what would have happened had the paramedics not performed a preemptive fluid bolus?
The paramedics withheld NTG for the remainder of the transport and repeated the fluid bolus of 500 ml 0.9% NS which brought the patient’s pressure back to 110/55 (almost what they started with).
On arrival at the hospital, the lead paramedic gave a report to the on duty ED physician, who was completely dismissive when the paramedic showed her the 12 lead ECG with lead V4 in the position of V4R.
Please note, I have the highest respect for the medical profession. I have nothing against emergency physicians. I’m just telling it like it was.
The physician immediately ordered NTG and morphine.
The paramedic sat down to write the report, and within 5 minutes he heard a nurse yell out “I need help in here!”
The patient was crashing. Fast.
Here is a 12 lead ECG that was captured after the patient’s pressure plummeted (I never found out how low it went).
In addition we now have ST-segment elevation in lead V1 (which is also associated with right ventricular infarction). Keep in mind that lead V1 is the only precordial lead on the right side of the patient’s chest.
The patient was stabilized after several tense minutes and sent up to the cardiac cath lab.
Here is an ECG taken before the intervention.