ST-elevation in aVR due to RCA occlusion

1 - Edited

Fig. 1

2 - Edited

Fig. 2

This is the case of a 56 year old male admitted 2 days prior for headache which turned out to be ICH patient was treated on a medical ward for this. His vital signs were stable and sustained no neurological deficits. The next evening, the medical on call was contacted for this patient for unilateral leg pain and swelling, which was appropriately investigated with doppler ultrasound. Results showed a DVT. The decision was made NOT to heparinize the patient due to his ICH. This decision was multidisciplinary involving the patient and family (including his son who is a HCP) with neurology and internal medicine. Next morning, the patient developed chest pain and the above EKG was taken see fig. 1.

A few minutes later the patient arrested and CPR was done as per ACLS protocol. This EKG was compared to the EKG done on admission, two days prior, see fig 2. So what was the reason for the arrest? The only investigation done prior to the arrest and subsequent death was the EKG in Fig. 1 This EKG has many telltale findings that could explain what made this patient arrest. There are ST-segment elevations in both the inferior leads and anterior leads. There is also ST-segment elevation in aVR of greater that 0.5 mV. There is pooled data demonstrating that this finding has approximately 78% sensitivity and 83% specificity for left main coronary artery disease.

Alternatively, this finding can also be the result of multi-vessel disease of acute proximal LAD or less commonly left circumflex or RCA.(1) To favor left main coronary artery occlusion ST-Elevation of AvR would be greater than that of V1, which is not the case in the above fig 1 EKG (2) In keeping with which territory the occlusion has occurred or what has caused the arrest, an ST-segment elevation inferiorly that is greater in lead III than in lead II, accompanied by ST-segment depression in lead aVL, I, or both, is 90% sensitive and 71% specific for right coronary artery occlusion. (3) With this evidence at hand, I believe this is more likely to be a very unlikely EKG presentation of RCA occlusion rather than a left main coronary occlusion. Furthermore, this extensive RCA occlusion was likely to be accompanied by RV infarction.

ST segment elevation is usually greater in lead III than in lead II when right ventricular infarction coexists with inferior AMI.(4) A coexistent reciprocal change with inferior STEMI is associated with larger infarct size and increased mortality.(5) A completely different theory was challenged. The patient had a DVT diagnosed and was not treated for it, then developed chest pain. Could the arrest and EKG finding be due to a PE? We know that PE can well cause ST-elevation in aVR. The fact that there is ST-depressions in lead I and aVL increases the sensitivity that this is AMI up to 84%.(6) Reciprocal findings are not present in PE. Also, PE does not cause ST-elevation in the inferior leads. And in keeping with AMI, the inferior leads have pathological Q waves. With all that said, my opinion is that this is a case of RCA occlusion with RV infarct, that caused the arrest of this patient.

Note! Consent has been taken from the patient’s son to publish the EKG.

References

1. Rostoff P, et al: Electrocardiographic prediction of acute left main coronary artery occlusion. Am J Emerg Med  2007 Sep;25(7):852-5.

2. Yamaji H, et al: Prediction of acute left main coronary artery obstruction by 12-lead electrocardiography. ST segment elevation in lead aVR with less ST segment elevation in lead V1. J Am Coll Cardiol 2001 Nov 1;38(5):1348-54. 

3. Zimetbaum PJ, Josephson ME: Use of the electrocardiogram in acute myocardial infarction. N Engl J Med 2003 Mar 6;348(10):933-40.

4. Zehmer U, et al: Effects of fibrinolytic therapy in acute myocardial infarction with or without right ventricular involvement. J Am Coll Cardiol 1998; 2:876

5. Martin TN, Groenning BA, Murray HM et al. ST segment deviation analysis of the admission of 12 lead ECG as an early diagnosis of AMI with cardiac Magnetic Resonance Imaging as gold standard. J Am coll cardiol. 2007;50(11):1021-1028. doi:10.1016/j.jacc.2007.04.090

6. Saw J, Davies C, Fung A, Spinelli JJ, Jue J: Value of ST elevation in lead III greater than lead II in inferior wall acute myocardial infarction for predicting in-hospital mortality and diagnosing right ventricular infarction. Am J Cardiol Feb 15;87(4):448-50, A6.

Educational Pearls (last week)

Good afternoon all, here are some points from our last academic activity entitled (The Immunocompromised Patient):

  • There are 2 types of immunity: innate which does not need previous exposure and acquired (adaptive) immunity which needs pervious antigen exposure .

 

  • The stem cell of bone marrow contains 3 times the number of WBC found in the circulation .

 

  • Pregnancy causes immunosuppression .

 

  • Cyclosporine is metabolized by cytochrome P-450, so try to avoid prescribing any medication that shares the same enzyme for metabolism, for example, a concomitant macrolide can cause hepatotoxicity or even rejection .

 

  • Corticosteroids:
    1. May cause change in WBC count as early as 6 hours from administration.
    2. Any abdominal pain in a patient who is on corticosteroid should be taken seriously and needs to be investigated for serious complications  such as perforated viscous and intra-abdominal abscess.
    3. Sutured wounds in patients on corticosteroids need double the time to heal (it affects healing).

 

  • Febrile Neutropenia:     ANC = WBC count * ((PMNs/100) + (Bands/100)).

Initiation of monotherapy with an anti-pseudomonal beta-lactam agent, such as cefepime, meropenem, imipenem/cilastatin or piperacillin-tazobactamCeftazidime monotherapy has also been shown to be as effective as other regimens .

  • HIV-positive patients: if CD4 is below 200 then this patient needs a prophylactic antibiotic for PCP.

 

  • 30% of elderly patients with infection will present without fever. Thus, absence of fever does not rule out infection.

 

  • 89% of elderly patients coming with fever will have an infection. (so deal with fever seriously in this group of patients).

MERS-Cov In Your ED!

To date, there are 133 deaths and nearly 500 confirmed cases of MERS-cov in Saudi Arabia alone. This means that there is not a major ED in KSA that has not seen at least one case. The risk is real. Presentations range. Talking to residents in our program, most have seen a case some have seen a few, this exceeds any other area in the world with a country as big as USA for example only having two.

The emergency department numbers over the past few months are quieter in the capital, Riyadh. With the worry of the same patient, one may ask is this corona or not?! Even the frequent flyer elderly who has had the same presentation of her pulmonary edema for the past 5 years due to her non-compliance to medication wants to know if this time it is corona or not! In April, as shown in the graph below from WHOthe majority of cases has been diagnosed. Could it be because we are screening more people?

Alqattan - Edited

 

 

 

 

 

 

 

 

 

Epidemic curve of 536 patients worldwide lab-confirmed cases of MERS-cov by outcome as of 8 may 2014

The biggest danger seems to be us, health care professionals. Sadly, we have lost consultants, residents and nurses to this disease. Precaution is vital. Person-to-person transmission has been documented. WHO as does the Saudi Authority M.OH, recommend droplet precautions as the disease. So wearing of a mask is important. All our triages give surgical masks to patients with a respiratory complaint. Anyone who may get in contact with secretions as for example those nurses and RTs doing suctioning or residents intubating should be more careful. This may include gowns in addition to gloves. Instruct family members who have accompanied the patient to do the same. The incubation period of the virus is 14 days.

Patients with MERS-cov may present with a mixture of upper and lower respiratory tract infection. This includes fever, cough, sputum, coryza. There are cases that presented with diarrhea in addition to above. Patients then go to acute renal failure. The mean age was 48.5 years but the youngest case in KSA was 9 months. Health care workers are more likely to be younger, female and milder disease. However, 15% of health care workers have been affected by a severe course of the disease, resulting in ICU admission or death. One confirmed case was a middle aged diabetic who came with altered mental status and a fever. The altered mental status turned to be due to a third degree heart block from a potassium of 7.5 from her acute renal failure from her MERS-cov! So presentations vary!

As for management and treatment, hospitals are requesting all admitted patients with suspicision to be swabbed. Some hospitals such as KFSH have opened itsPCR for twice daily due to the influx. Treatment is supportive care and symptom relieve.

Trauma Review

May has proven to be a very eventful month in KSA with many international speakers dropping by from the world of emergency medicine. This week we had the pleasure of meeting Dr. Swaminatha V. Mahadevan, associate professor of surgery and emergency medicine and director of international emergency medicine in Stanford University to give us a talk on trauma. The discussion was very interesting as West meets East in comparing practices!

First stop was the use of video laryngoscopy. Should video laryngoscopy be standard of care or should it be used as an adjunct in the management of emergency medicine? Video laryngoscopy has proven to have no difference in mortality compared to direct even though it took on average 16 seconds longer (Yeats et all. 2013. J Trauma Acute Care Surg: 75:212-9). In teaching intubation, video laryngoscopy provides a more relaxed and in-control environment as performer and teacher have equal views. Even though direct laryngoscopy is not out of the window yet, video laryngoscopy is definitely taking over.

Next stop was the use of massive transfusion protocol. Massive transfusion protocol and giving blood, plasma and platelets at a ratio of 1:1:1 has really changed the practice of trauma resuscitation. Thanks to the PROMITT study which has decreased 6 hour mortality with the above ratio. Patients with ratios of 1:2 were 3-4 times more likely to die than patients with 1:1. When do you apply it? The definition of Massive transfusion is when the patient is anticipated to loose his blood volume in 24 hours, i.e., 10 units. The Europeans advocate to start the protocol after 4 units of PRBCs while other guidelines suggest to start with a base excess >5, INR ≥1.5, hemoperitoneum (Hsu et al. 2013. J Trauma Acute Care Surg: 75:359).  How to apply it? Dr Mahadevan shared with us Stanford’s protocol that , 1 unit of FFP can be given for every 1 unit PRBC, after 10 units of each, 6 units of platelets are given.

Next was a very heated debate of head trauma in the anti-coagulated patient. A headache to both the patient and EM physician! The CT comes back negative but you are not done! The medical literature is quite lacking here with many questions still not answered. How long to observe? Indications for serial CTs? Will it go from a negative CT to a neurosurgical emergency? Who do you reverse the INR? The literature has failed to identify which patients at low risk of ICH, even in the absence of clinical findings and therefore an initial CT is warranted (Joesph et al. 2014. Am Surg: 80:43-7). After that, observation of at least 24 hours is key. Any change in level of consciousness, alertness, and neurological function buys this person a CT brain. In the presence of an intracranial bleed INR reversal is achieved with 4 factor PCC and slow infusion of IV vitamin K with INR monitoring. The decision to reverse the coagulation though life saving should not be taken lightly as the patient was on warfarin to prevent thrombosis whether it is a recurrent PE or a metallic valve.

Last, was the use of Ultrasound in trauma. This topic does not need an introduction ultrasound is used extensively here. Procedures are safer with ultrasound. Ultrasound has proven to be more sensitive than a chest x-ray at detecting a pneumothorax (Nagarsheth et al 2011. Am Surg: 77: 480-4). And of course ultrasound for E-Fast is well established in the literature.

Thank you Dr. Mahadevan for taking time off to meet the residents of SPEM and we look forward to seeing you again.

Thoracic Trauma

Good afternoon all,

Here are some points from our last activity (Thoracic Trauma) that took place in 22-04-2014

1-The most common chest injury in pediatrics is lung contusion. While the presence of rib fracture means sever trauma.

2-1st and 2nd ribs fractures are not always an indication for angiography as it depends on clinical suspicion.

3-Lower ribs fractures (9-12) :

A-If on the right side:  3 × times increase in risk of liver injury.

B-If on the left side:  4× times increase in risk of spleen injury.

4-Any displaced rib fracture needs observation and monitoring for at least 3 hours and chest x-ray needs to be repeated before discharge.

5-Isolated sternum fracture does not reflect cardiac or aortic injury.

6-In blast injury (shock wave) pulmonary contusion can present even without any external evidence of chest injury.

7-ARDS vs lung contusion :

Contusion will appear within the first 6 hours while ARDS will take longer time to manifest.

8-80 %  of tracheobronchial injuries are within 2 cm above the carina, suspect it when you have a continuously leaking chest tube .

9-Myocardial concussion (Commotio Cordis): blunt injury to the chest produces a stunned myocardium and dysrhythmias (mostly  Vfib).

10-There is no single test that confirms the diagnosis of cardiac contusion except for autopsy.  Thus, the key point whenever it’s suspected is monitoring (serial ECG, cardiac markers).

11-In myocardial rupture the most common affected part is ventricles (Rt more than Lt).

12-Aortic injury is the most common vessel injury with 80-90% of injuries in the descending part just distal to the Lt subclavian artery.  The most indicative CXR finding is widened mediastinum .

13-Esophageal rupture:  almost 100%  mortality if the diagnosis has been delayed for more than 24 hours.  Gold standard test is gastrografin esophagram but it will be suboptimal in case of multiple trauma where the patient is only in supine position as it needs different views while standing in different positions, i.e. AP, oblique and lateral so in this case  you need to add endoscopy to support the diagnosis and if esophageal rupture is still suspected go to surgery .

14-The most common side of diaphragmatic rupture is the Lt side and it is mostly caused by a blow to the abdomen that raises the intrabdominal pressure too high to a limit that causes the diaphragm to burst.