This patient presented to the emergency department with acute pleuritic chest pain, dyspnea, and experienced a cardiac arrest prior to a detailed physical examination. The cardiac monitor shows a narrow complex sinus rhythm morphology. In the setting of a cardiac arrest and pulselessness, this cardiac rhythm is known as pulseless electric activity (PEA). PEA includes any cardiac rhythm that is not asystole, ventricular fibrillation, or pulseless ventricular tachycardia. The ACLS algorithm divides the management of patients with pulseless ventricular tachycardia (pVT) or ventricular fibrillation (VF) and patients with pulseless electric activity (PEA) or asystole. Assuming adequate staff and medical resources are present, patients with all of these rhythms receive high-quality CPR, IV epinephrine, and airway management. Patients with pVT or VF receive electrical cardioversion, while patients with PEA or asystole do not receive electrical cardioversion. Patients with PEA or asystole generally have a poorer prognosis than those with pVT or VF. Out of hospital cardiac arrests that present to the emergency department with PEA or asystole on initial rhythm have a survival rate of under 3%. The etiology of PEA in cardiac arrest includes a wide variety of causes. A traditional approach to remembering the reversible causes of PEA are the “Hs & Ts”. The list of the “Hs & Ts” along with their individual treatments are listed in the table below.
Sodium bicarbonate (Choice A) would be the correct choice for a patient whose PEA arrest was caused by severe acidosis. This can occur in severe lactic acidosis (i.e. sepsis), diabetic ketoacidosis, certain toxic ingestions (i.e. iron, salicylates, tricyclic antidepressants), as well as other causes. Calcium gluconate (Choice B) would be the correct choice for a patient whose PEA arrest was caused by hyperkalemia. This can occur in renal failure, in the setting of certain medications, rhabdomyolysis (muscle tissue breakdown), and other causes. Blood products (Choice D) would be the correct choice for a patient whose PEA arrest was due to severe hemorrhage, such as gastrointestinal bleeding or in the setting of traumatic injuries. This patient has symptoms and risk factors for pulmonary embolism, including pleuritic chest pain, dyspnea, and a cancer history. These details make pulmonary embolism the most likely cause of PEA arrest in this scenario. The best treatment for this diagnosis would be thrombolysis (Choice C).
This patient presents to the Emergency Department after a cardiac arrest with an unknown medical history. Important components of Basic Life Support (BLS) include early initiation of high-quality CPR at a rate of 100-120 compressions/minute, compressing the chest to a depth of 5 cm (5 inches), providing 2 rescue breaths after every 30 compressions (30:2 ratio), avoiding interruptions to CPR, and allowing for adequate chest recoil after each compression. In the Advanced Cardiovascular Life Support (ACLS) algorithm, intravenous epinephrine is administered every 3-5 minutes and a “pulse check” is performed after every 2 minutes of CPR. The patient’s cardiac rhythm, along with the clinical history, helps decide if the patient should receive additional medications or receive unsynchronized cardioversion (defibrillation, or “electrical shock. The ACLS algorithm divides management in patients with pulseless ventricular tachycardia (pVT) or ventricular fibrillation (VF) and patients with pulseless electric activity (PEA) or asystole.
The cardiac rhythm seen during the pulse check for this patient is ventricular fibrillation. The ACLS algorithm advises unsynchronized cardioversion at 150-200 Joules for patients with pVT or VF. Continuing chest compressions (Choice A) with minimal interruptions is a crucial component of BLS, however, this patient’s cardiac rhythm is shockable. Defibrillation (Choice B) takes precedence over CPR in this scenario. Amiodarone (Choice C) is an antiarrhythmic agent that is recommended in patients with pVT, in addition to unsynchronized cardioversion. This patient has VF, not pVT. Sodium bicarbonate (Choice D) is an alkaline medication that is helpful in cardiac arrests caused by severe acidosis or certain toxins (i.e. salicylates or tricyclic antidepressants). The next best step in this patient scenario would be defibrillation for the patient’s VF (Choice B).
For medical students! – Question of The Day – A 68-year-old man presents to the Emergency department after a witnessed collapse. ❓Which of the following is the most appropriate next step in management for this patient’s condition ❓ pic.twitter.com/N5HIjINtpx
A 52-year-old woman presents to the ED from an outpatient dialysis center with a rather vague history. She has no symptoms and feels normal, but she was told something “was either too low or too high” on her vital signs at dialysis, so dialysis staff did not perform her scheduled dialysis session. No one had called ahead to alert the emergency department, and the patient had driven herself to the ED, as she was instructed. Vitals show a normal temperature, respiratory rate, oxygen saturation, blood pressure of 102/47 mm Hg, and a heart rate of 138 beats per minute. The physical exam is normal besides a mild regular tachycardia and a working AV dialysis fistula on the right arm. EKG is done, and a representative portion is shown below:
EKG from the prior year is shown for comparison.
How would you interpret the first EKG, and what are your next steps?
Discussion
While you are thinking, I will discuss a few of my practical observations from working in the pit. I want to focus not so much on the diagnosis but on working with these types of scenarios.
Treat the patient and not the chief complaint, vitals, labs, EKGs, studies, or referral information.
When they are feeling great and have no symptoms, they are feeling great and have no symptoms! Your nurses will not necessarily think this way, but one does not feel great while having a real STEMI apparent on the triage EKG. So what is it then, if the patient is here for a contact lens stuck in their eye, but has an EKG STEMI? Worst case – a prior STEMI that never corrected or evolved on the EKG. A ventricular aneurysm? Leads misplaced? Did your EKG tech do an EKG on themselves? A silent MI can occur, but an incidental STEMI is unlikely.
Of course, the patient has to be alert, competent, and not intoxicated. They should not be lying about or hiding their symptoms and should not have a secondary interest like the need to make it to a daughter’s wedding - live or die. The easiest thing is to ask directly.
What is the rhythm's rate doing when it is left alone?
Afibs and MATs will tend to vary greatly in the second to second heart rate, sinus tachycardias will fluctuate some, while A-flutters and SVTs will tend to stick to a single number no matter what you do and no matter if the patient is walking, talking, or snoozing. Stable Vtachs will depend on a number of factors like being monomorphic or polymorphic – but we are talking about narrow QRS dysrhythmias or ones with an obvious bundle.
So if you cannot tell from the EKG – observe what the thing does while left alone. As long as the patient is otherwise stable or has had symptoms for a while, you have some time.
Adenosine – not just for SVT conversion
“SVT = adenosine” should not be an automatic equation. First of all, there are contraindications to adenosine based on past history or current medications taken. But adenosine can also be used to “stretch out” weird or equivocal fast rhythms to make flutter waves or hidden P waves come out, so you can see and diagnose the arrhythmia vs. sinus.
You have to have continuous EKG recording going or printing the monitor strip to spot the temporary effect.
Hypotension + tachy-dysrhythmia: does not necessarily add up to Joules.
The textbook mantra of shocking any dysrhythmia associated with hypotension does not hold up in reality. In reality, you will find that most of your Afibs with a rapid response, your new-onset atrial flutters and your SVTs will have a lousy blood pressure: systolic of 80s and 90s are almost to be expected, and may even dip down to 70s on occasion. It also depends on a prior BP baseline, if the person is petite or dehydrated. But if the patient is mentating well and is not suffocating or experiencing crushing chest pain with diaphoresis, please don’t feel like you have to shock them. The body is not used to the new arrhythmia, and the rapid rate compromises the cardiac output.
Yes, you can still use your rate and rhythm controllers. Give the patient a gentle fluid bolus if you must. Of course, pacer pads do have to be on ahead of time.
Be afraid of shocking dialysis patients. Check electrolytes.
Hypotension with normal mentation is much better than a PEA arrest. Shocking extremes of electrolyte and acid/base abnormalities, whether due to TCA and other overdoses or in dialysis patients, will give you exactly that. This is especially true for the so-called “slow-X” arrhythmias: slow Afib, slow SVT, or even V-slow (Vtach with a rate of 130) that dialysis patients like to present in.
Just like airplane travel in transportation, electricity is in general the safest rhythm conversion strategy. But there are exceptions, and you only need to crash once.
A-flutter and the stuck rate of 150
You already know this, but just as a reminder. If the rate is a steady 150, plus or minus, and it is stuck there, you should think of atrial flutter.
Even if you do not see obvious classic flutter waves, there is a high chance of 2:1 conduction. In this case, I thought of it. Fortunately, it did not think of me.
Adenosine (again)….the 6, the 12…the 24??
Sometimes adenosine is not pushed correctly, but sometimes it just does not work or only works for a few seconds. Sometimes the patient’s Mom knows best what works, so you should listen. Sometimes the last time it was used, the patient really did feel like they were going to die – so they do not ever want it again. Ever. That you should try 6mg, then 12mg, then stop is generally true, but it is also a dead-end. What is your back up plan? Electricity? In the past I have given the doses in reverse, combined 6mg with the Valsalva maneuver and had given a preemptive beta-blocker or calcium channel blocker dose 10-15 minutes before adenosine to massage a stubborn heart into adenosine submission. It is ok to experiment a little. Another practical point – how much does your ED freak an SVT patient out while he or she is being triaged and roomed? I still do not completely understand why an SVT tends to be rushed up in the same fashion as a STEMI with cardiogenic shock and bradycardia, judging from staff adrenaline levels.
Calm the patient down, turn the lights off and let them change. It's like a kid with croup. Remember, it is lack of the sympathetic influx that we want, not an excess. Otherwise, why try the Valsalva at all? Has anyone attempted a stellate ganglion block Vfib-style for a refractory SVT? An overkill, I know….but could be fun, and practice for the real deal.
Aren’t all AVNRTs verapamil sensitive?
Years ago, in my first year of solo practice, I had a case of a refractory SVT in a young teenager, which a pediatric cardiologist consulting by phone called a “verapamil-sensitive AVNRT” based on the EKG alone. I was impressed. Hours later, I decided to flash my newly acquired cool knowledge and relayed the same to my in-house cardiologist, who looked at me with a grin and a raised eyebrow and said, “Anthony, all AVNRTs are verapamil sensitive”. At that time, I was also sensitive, and so my feelings were hurt. Lately I have gotten into the habit of treating my SVTs with diltiazem – as a purer verapamil relative. With generally good results and no need to stand in front of the patient during administration by the nurse.
The bottom line is – you have choices. Especially, if the patient is already on a beta-blocker or a calcium channel blocker, give them a beta or a calcium blocker IV, see what happens.
Case Concluded
Despite a single nadir of blood pressure of 75 systolic, the rest holding steadily in the high 90s, the patient received a single dose of IV diltiazem and a small IV fluid bolus. Labs reviewed prior showed normal potassium, calcium, sodium, magnesium and the rest of them. Her average heart rate reduced to about 106 and a repeat EKG is shown, accidentally capturing an event:
She, of course, had a “verapamil sensitive” SVT. The patient’s new right bundle block had also improved to an incomplete, proving to be either SVT- or rate-related. The patient had never experienced any symptoms while in the ED. She was observed for a short time, scheduled for an out-of-sequence dialysis the next day and discharged home with a normal heart rate. I guess, in this case, we did treat the EKG and not the patient.
This patient has a narrow-complex tachycardia with a regular rhythm. A narrow QRS complex is defined as a QRS interval less than 120msec. This is a normal finding. The differential diagnoses for regular narrow complex tachycardia include sinus tachycardia, atrial tachycardia, atrial flutter, and supraventricular tachycardia (“SVT”). SVTs are typically associated with narrow QRS complexes, unless there is a concurrent bundle branch block, other aberrant conduction, or the existence of electrical accessory pathways as in Wolff Parkinson White (WPW) syndrome. The heart rate of an SVT can vary from 140-280 beats/min. Intravenous Adenosine (Choice A) is a hallmark of SVT treatment, however, Adenosine is given after vagal maneuvers have been attempted and have failed. Synchronized cardioversion (Choice B) is a last-ditch effort treatment in a patient with SVT. Vagal maneuvers and medications are attempted prior to using cardioversion. However, if the patient is hypotensive, cardioversion should be employed. Intravenous Amiodarone (Choice C), beta-blockers, calcium channel blockers, or other antiarrhythmics can be used to terminate SVTs if vagal maneuvers and adenosine are not effective. Vagal maneuvers (Choice D), such as the Valsalva maneuver (“bearing down”) or carotid massage, are the initial treatment for SVTs. Correct Answer: D
❓Which of the following is the most appropriate next step in management for this patient’s condition? – ❓A detailed answer will be found in https://t.co/XvqTTNtHys on Friday 11 PM UK time.