Cardiac Emergencies

STEMI, NSTEMI, CHF, hypertensive emergency, tamponade, dissection, aneurysms, A-fib RVR and symptomatic bradycardia.

Common Emergency Conditions: Workup, Treatment, Nursing Tips

Cardiac Emergencies

STEMI

• An ST Elevation myocardial infarction is full blockage or near full blockage of a coronary artery that occludes blood flow to that section of the heart. If left untreated, cells will begin to die off, and it will eventually affect the heart muscle and how it contracts. The ST elevation will be seen in consecutive leads, pointing to which artery is occluded (see ECG section for details). o The patient can present with pressure like chest pain, shortness of breath, nausea, diaphoresis, paleness. The CP often radiates to the neck, jaw and arms. o Do keep in mind that a STEMI may also present differently in women and diabetic patients with symptoms such as epigastric pain, nausea and a feeling of impending doom. Often described as "Something's just not right." • Specifics of the Workup o ECG: Should be done within 10 minutes of patient arrival to the ER. The faster a STEMI is caught, the faster reperfusion therapies occur and the more cells/muscle is saved. o Labs ▪ Cardiac Enzymes: Troponin (Troponin will start to rise at hour 2) which is why ECG is very important to detect early ▪ Baseline labs like CBC, BMP, Coags o These patients may also get a chest x-ray and bedside ultrasound by providers, BUT when a STEMI is identified, it should take priority unless there is a high suspicion of other causes. • Treatment o Reperfusion Therapy is the Definitive treatment ▪ PCI or Percutaneous Coronary Intervention is preferred as it is more likely to be successful in opening the occluded artery and perfusing the heart. It also doesn't come with the bleeding risks associated with giving a thrombolytic. ▪ If PCI is not available or the nearest hospital with PCI capabilities is too far, a Thrombolytic will be administered to break the occlusion/clot up. This can be Tenecteplase or Alteplase. • A thrombolytic will break up the blockage, restoring blood flow. As the nurse you will need to closely monitor this patient for signs of serious bleeding such as a head bleed or GI bleeding (gum bleeding is not too concerning), plus continuously monitor vitals and ECG rhythm for any changes. • Contraindications for thrombolytics: Active Bleeding or Bleeding conditions like hemophilia, recent surgery or head bleed or trauma, uncontrolled hypertension among others o Provide Oxygen: Keep SPO2 above 95% o Medications ▪ Aspirin: An antiplatelet, essentially helps by preventing the clot from getting bigger. For adults, the typical dose will be 324mg. • Ensure the patient is not allergic and there are no signs of acute bleeding. • If allergic, Plavix should be given. It is also an antiplatelet that helps prevent the clot from getting bigger. ▪ Nitroglycerin: Helps dilate coronary arteries, which improves blood flow to ischemic area and helps oxygenate ischemic cells. As discussed it also helps with preload and afterload reduction, which decreases the workload on the heart, demanding less from it. • Contraindication: Do not administer nitroglycerin with Right Sided MI's, which can be evidenced by ST Segment elevation in inferior leads (II, III, AVF) (a right sided ecg should also be performed here). The right side of the heart fills passively, if you decrease preload, you are decreasing the amount of blood returning to the heart, and as a result decreasing cardiac output because there is less blood to be pumped out. o Also avoid if pt is on sildenafil. ▪ IV Fluids • If it is a right sided MI and the patient is hypotensive, IV fluids may be ordered to help increase preload. ▪ Heparin • One of the main reasons for getting heparin is if the patient is going for PCI, it will help prevent blood clot formation on the stent, helping keep it open. • Of course, the other is that it helps prevent the clot from getting bigger. • Nursing o Place Pads on the patient and closely monitor ECG rhythm as the heart is irritable/ischemic and may suddenly go into Vfib, Vtach or even into a block if the SA node is affected. o Place IV on the L side if possible. Cardiologists typically use the R radial for cath lab procedures. o If no immediate cath lab capabilities in your area, you must be familiar with contraindications for thrombolytics and monitor closely for bleeding if thrombolytics are given. ▪ If thrombolytics give, be aware of reperfusion injury. Since there was no blood flow and perfusion to cells, acids and inflammation began to build up and when reperfusion occurs, these harmful substances are sent out to the body. Plus those ischemic cardiac cells underwent changes and now that oxygen and perfusion have returned, they can be further damaged as a result.

NSTEMI

• A Non-ST Elevation myocardial infarction is partial blockage of a coronary artery that decreases blood flow to that section of the heart. If left untreated, cells will begin to die off, and it will eventually affect the heart muscle and how it contracts. o The patient can present with pressure like chest pain, shortness of breath, nausea, diaphoresis, paleness. The CP often radiates to the neck, jaw and arms. o Do keep in mind that a NSTEMI may also present differently in women and diabetic patients with symptoms such as epigastric pain, nausea and a feeling of impending doom. Often described as "Something's just not right." • Specifics of the Workup o ECG: Should be done within 10 minutes of patient arrival to the ER. It can detect signs of ischemia such as T wave inversions and ST-segment depression o Labs ▪ Cardiac Enzymes: Troponin (Troponin will start to rise at hour 2) which is why ECG is very important to detect early ▪ Baseline labs like CBC, BMP, Coags o These patients will also get a chest x-ray and bedside ultrasound by providers. And if indicated, additional testing like CT cans, may be ordered. • Treatment o Aspirin: An antiplatelet, essentially helps by preventing the clot from getting bigger. For adults, the typical dose will be 324mg. ▪ Ensure the patient is not allergic and there are no signs of acute bleeding. ▪ If allergic, Plavix should be given. It is also an antiplatelet that helps prevent the clot from getting bigger. o Provide Oxygen: Keep SPO2 above 95% o Analgesia: Morphine or Fentanyl ▪ Give slowly, especially in elderly. Keep an eye on respiratory drive and if needed place on endtidal CO2. But if you give slowly, should have no serious side effects. o Nitroglycerin ▪ Helps dilate coronary arteries, which improves blood flow to ischemic area and helps oxygenate ischemic cells. As discussed it also helps with preload and afterload reduction, which decreases the workload on the heart, demanding less from it. o Heparin Bolus and Infusion ▪ An anticoagulant that prevents the occlusion from getting worse, giving the body time to start breaking down the clot on its own. When on the heparin drip, you will repeat the PTT (might be all the coags at your facility) at a set amount of time, to ensure that the patient is at a therapeutic level of heparin, typically ranging between 60-90.(This changes a bit by institution so know yours). • Monitor your patients for signs of bleeding. • Before starting the heparin infusion, you will need a baseline hgb, hematocrit and coags, plus ensuring there are no signs of bleeding such as dark black stools prior to infusion. (You don't want to make bleeding worse, however, sometimes benefits vs risks play a role) • Nursing o You may be asking, well if there is a clot, why aren't we breaking it down with a thrombolytic? Since there is still blood flow and perfusion as the coronary artery is not fully blocked, the risk of severe/deadly bleeding with a thrombolytic is not worth the risk. o Giving aspirin and starting a heparin infusion give the body time to start breaking down the partial occlusion. ▪ HOWEVER, these patients will still most likely undergo a diagnostic angiogram in the cath lab and if needed, a stent will be placed there (or other treatments like CABG-based on what cardiology recommends). ▪ ALSO, we will continue to closely monitor these patients, ensuring the ischemia and damage to the heart is not worsening, and if it is, it warrants the patient go to the cath lab faster and undergo PCI. • We monitor by repeating the ECG and troponins Q4H, Q6H, or Q8H or whatever cardiology recommends. If the troponin starts to rise and there are more changes to the ECG, again, that is when PCI is indicated. • We also closely monitor the patient for worsening signs and symptoms such as worsening or new chest pain, shortness of breath, diaphoresis, nausea or even new arrhythmias. o As the RN, you will carry out the interventions and closely monitor, promptly communicating with the team.

Congestive Heart Failure Exacerbation

• The heart is weak and or stiff, making it unable to pump blood effectively to meet the body's demands. As a result, there is fluid backup into the body. Fluid builds up in the lungs and rest of the body, particularly the lower extremities in the form of pitting edema. o The patient can present with shortness of breath, weakness, dizziness, peripheral edema and chest pain. • Specifics of the Workup o ECG: identify arrhythmias and any ischemic changes. o Chest X-ray: assess for pulmonary edema and cardiomegaly. o Echocardiogram: assess cardiac structure and function, including ejection fraction o Brain natriuretic peptide (BNP): assess severity of CHF and confirm diagnosis • Treatment o Oxygen, Monitor, IV o Nitroglycerin ▪ A vasodilator that reduces preload and afterload. By decreasing the amount of blood returning to the heart (preload), the workload on the heart goes down. By decreasing systemic vascular resistance (afterload), there is less resistance to pump against, making it easier for the heart to pump blood out. This combination of decreasing preload and afterload improves cardiac output. ▪ Also does dilate coronary arteries, increasing perfusion and oxygenation to heart muscle. This is why it is used for angina. • Also avoid if pt is on sildenafil. o Furosemide (Lasix) ▪ A diuretic. Through diuresis, preload is decreased because there is less blood volume returning back to the heart, further decreasing the workload of the heart. (Diuresis is the key with CHF because getting fluid out is what will mainly treat the patient) o BIPAP (Bilevel positive airway pressure) ▪ By providing positive airway pressure during inspiration and exhalation, collapsed alveoli are opened and the pressure forces fluids out of the lungs. Making it easier to breathe and oxygenate. o Reverse cause of exacerbation if known such as an arrhythmia, anemia, ACS, drugs (cocaine, meth) etc • Nursing: Be proactive with assisting your patient to urinate after lasix(Urinal, Bedside commode, purewick) since that is how they will get better and strict I/Os o For IV placement, hold pressure on site until edema subsides enough for veins to be palpated and IV placed, use a longer catheter

Hypertensive Emergency

• To qualify as a hypertensive emergency there, have to be signs of end organ damage. End organ damage would be exhibited on the workup and physical assessment. Are there ECG changes, renal or heart injury in the labs? Is the patient actively experiencing chest pain, sob, dizziness, headaches, nausea? o There will most likely be a cause for the hypertensive emergency and it must be addressed. Issues such as medication noncompliance, renal disease, heart failure, drug use or uncontrolled hypertension may be a cause. • Specifics of the Workup (aimed at identifying causes and severity of end organ damage) o Labs: ▪ BMP: Assessing Electrolytes and ensuring nothing is missed ▪ CBC: Abnormalities in the CBC can help guide towards more uncommon causes ▪ Kidney Function: Creatinine, GFR, BUN (Assess for kidney damage) ▪ Cardiac Enzymes: Troponin and BNP (Assessing for damage or strain on heart muscle) ▪ Urinalysis: Assessing for protein or blood in urine (kidney damage) o Chest X-ray: assess for pulmonary edema and cardiomegaly o ECG: identify arrhythmias and any ischemic changes. o CT: When indicated based on symptoms and physical, for example, a head CT for a hypertensive patient with neurological deficits to rule out intracranial issues like a brain bleed • Treatment o In a true hypertensive emergency, the MAP (Mean Arterial Pressure) should be lowered by no more than 20% in the first two hours. End organ damage was occurring as a result of the BP being too high, you do not want to further contribute to the damage through hypoperfusion. ▪ Of course, there are times when the BP should be rapidly lowered such as with brain bleeds. o Medications ▪ The medication used to the lower the bp will depend on the patient and cause. ▪ Slow IV Push Medications • Labetalol o A beta blocker used to rapidly lower BP as a slow IV Push over 2 minutes. Typical dosing in adults may range from 10-20 mg. May repeat dosing. o It will lower the BP while having minimal effects on cardiac output. o Onset is within 5 minutes and can last up to 4 hours. o Considerations ▪ It is a beta blocker. If the heart rate is less than 60, or even on the lower side nearing 60, a different agent should be used so the heart rate does not drop, causing other issues. ▪ While actively giving, set BP to take Q5 minutes to monitor effects closely. ▪ Avoid in Asthma, COPD, heart blocks, and of course when the patient is bradycardic and or hypotensive. ▪ Whenever giving an antihypertensive, have a very recent last set of vitals. • Hydralazine o An arterial vasodilator that helps decrease BP. It can be unpredictable in how much it drops the bp, which is why it is often used second to Labetalol when an IVP med is needed. It may cause reflex tachycardia. o Adult dose is typically 10-20 mg per dose. o Onset is within 5-10 minutes and can last up to 2-4 hours. o Considerations ▪ Whenever giving an antihypertensive, have a very recent last set of vitals. ▪ While actively giving, set BP to take Q5 minutes to monitor effects closely. ▪ Infusion / Drip Medications • Nicardipine (Cardene) o A CCB that is frequently used as an infusion to bring BP when no special considerations are present. o Start Dose will often be 5mg/hr, titrate by 2.5 mg q 5-10 minutes, max of 15mg/hr. o Onset is within 5-10 minutes, duration 4-6 hours o While actively giving, set BP to take Q5 minutes to monitor effects closely. • Nitroglycerin o Will primarily be used to lower BP as an infusion with congestive heart failure exacerbations when the BP is high as a result of volume overload. o Many times it will be used for a short period of time to stabilize the patient while in the ER, then will be discontinued prior to admission if pt is stable o Onset is within 2 minutes, lasts up to 10 minutes o Infusion start dose is typically 5mcg/min, titrate by 5-10mcg q 5 minutes, with a common max from 100-200mcg/min. (Please verify drips/infusions start rates, titrations, and max with your own facility's protocols) o While actively giving, set BP to take Q5 minutes to monitor effects closely. ▪ Also avoid if pt is on sildenafil. • Esmolol o A cardioselective beta blocker. In the ER, I have only used it for bringing the BP down in aortic dissections and for bringing the HR down in Afib RVR. Therefore, you will most likely not see it as an antihypertensive in other conditions. ▪ It slows the HR down, therefore decreasing cardiac output and BP. ▪ Useful in Dissection because you don't just want to give a med that will only lower the BP, the body will respond to this by increasing the HR and contractility, which will make the dissection worse. Esmolol helps with both bringing the HR down and BP. o Fast on fast off. Onset within 1 minute and duration of only up to 9 minutes. o Adult dosing with an infusion will typically require a loading dose followed by 50mcg/kg/min, titrating by 50mcg/kg/min q 5-10mins, max of 200mcg/kg/min (Please verify drips/infusions start rates, titrations, and max with your own facilities protocols) • Nursing: Recheck the BP, ensure cuff is correct size and place appropriately. While actively giving BP meds, set your Bp q 5 minutes to closely monitor patient response. Give the meds time to work (don't keep stacking titrations without giving appropriate time to work).

Cardiac Tamponade

• Fluid accumulates around the heart, this compresses the heart preventing cardiac filling and effective contractions, ultimately leading to decreased cardiac output and shock. o Causes can include pericarditis, penetrating chest injuries and as a result of fluid overload such as a renal patient who has missed dialysis o Patients can present with shortness of breath, chest pain, distant heart sounds, jugular venous distention and signs of shock such as tachycardia, hypotension, dizziness, pallor, diaphoretic and so forth. (These patients sometimes look like CHF patients) • Specifics of the Workup o ECG: Can show ST changes throughout all leads, can also have small low voltage QRS o Chest Xray: Findings can point the provider towards pericardial effusion and cardiac tamponade o Ultrasound: Bedside Ultrasound by your ER provider to help confirm diagnosis or formal echocardiogram if readily available o Labs: Can include Troponins and BNP o CT: A chest CT may be indicated if Chest xray and bedside ultrasound are not conclusive and more details are needed • Treatment o Pericardiocentesis ▪ Removes the fluid around the heart. Typically a needle is inserted to reach the pericardial sac with the guidance of ultrasound and the fluid is aspirated. o IV fluids: A bolus may be administered to help with preload and cardiac output while providers prepare for pericardiocentesis. This is only a temporary stabilizing treatment. o Vasopressors: Dobutamine may be used to help the heart contract better while providers prepare for pericardiocentesis. This is only a temporary stabilizing treatment. (I've also used norepinephrine in these situations). • Nursing o Your role as the ER nurse with the pericardiocentesis, besides ensuring consent and time out, will be to ensure your patients has support (its stressful feeling sick and docs telling you they are going to stab you in the chest), place them flat or slightly elevated, monitor vital signs closely and keep an eye out for arrhythmias(anytime you mess with the heart, it can go into an arrhythmia).

Aortic Dissection

• A tear happens in the wall of the aorta and blood is able to escape into this tear, separating the layers of the aortic wall. If left untreated, blood will continue to enter, leaving less and less blood to perfuse organs. It can also cause the aorta to rupture and the patient bleeds out internally. o Causes include untreated hypertension and connective tissue disorders o Patients will present with sharp or tearing chest or back pain, shortness of breath, pallor and overall signs of shock. Pt can also have a difference in BP from R to L arms. The decreased perfusion to organs can present as symptoms of that organ system for example decrease perfusion to brain may exhibit stroke like symptoms. • Specifics of the Workup o CT Angiography: Main diagnostic study to help providers diagnose an aortic dissection. Will tell us where it is and how severe. o Labs: CBC, BMP, Renal Function, Cardiac Enzymes, D-Dimer. Coags. Type and screen. ▪ Function tests like renal and cardiac are to eval extent of injury from hypoperfusion ▪ D-Dimer and coags will help with assessing clotting issues as a result of clotting factors and blood being used up by the dissection ▪ Type and Screen for surgery o ECG: Assess for any ischemic changes to the heart and or arrhythmias (I've taken care of patients whose dissection was big enough to tamper with blood flow going to coronary arteries) o Chest xray: Findings can point the provider towards dissection • Treatment o Surgery is the definitive treatment for aortic dissection o Blood Pressure Control ▪ To prevent dissection from worsening, GOAL is an SBP less than 120 (ideally around low 100's) ▪ Esmolol is great because as described earlier it helps bring the heart rate and BP down. • If esmolol alone does not produce desired effects, may add Nicardipine (cardine) on top (I have had pts on both esmolol and cardene to keep Bp and HR at desired goal) ▪ Pain medications • Pain increases HR and BP. I primarily have given Fentanyl doses in the past, but have also seen morphine be used. • Nursing o Assess BP q 5 minutes on Right Arm to ensure close monitoring (ask for an A line). You will be giving several doses of pain meds so give slowly and monitor for respiratory depression (Place pt on Endtidal CO2). If a dissection is suspected early on, ensure you are communicating with radiology so your patient goes early for CT. These patients can tank pretty quickly, so ensure you are also communicating with Surgery team. Have at least two good working IV's.

Thoracic and Abdominal Aneurysms

• Aneurysms are a weakened part of the aortic wall that dilate and bulge, can ultimately rupture and the patient can internally bleed out. • Thoracic Aneurysm: Can involve the ascending aorta, aortic arch and descending aorta. o Patients can present with tearing or sharp chest or back pain, difficulty breathing and hoarseness or difficulty swallowing depending on location. ▪ If large enough it may also present as signs of shock. ▪ There may be differences in blood pressure between L and R arm, depending on where the aneurysm is. • Abdominal Aneurysms: Will involve the descending aorta o Patients can be asymptomatic or present with abdominal pain or back pain, a pulsating abdominal mass and or if large enough, may also present with signs of shock. • Specifics of the Workup o CT Angiography: Help identify the presence, size and location o Ultrasound: Can also help identify the presence and size, however, CT is preferred o Labs: Aimed at identifying complications such as end organ damage and to obtain a baseline or identify comorbidities that may be present ▪ CBC, BMP, Renal Function, Cardiac Enzymes, Coags, Type and Screen o ECG: Assess for any ischemic changes to the heart and or arrhythmias o Chest x-ray: as part of the initial workup prior to diagnosis being made • Treatment o Surgical Repair or Stent/Graft Placement o Blood Pressure Control ▪ Esmolol and if needed adding Nicardipine on top (Just as we discussed for dissection) ▪ The goal is an sbp less than 120 o Pain Control ▪ Pain increases HR and BP. Will either give fentanyl or morphine (Just as we discussed for dissection) • Nursing o As with any other critical patient have 2 good working IV's, especially with these patients as they can tank fast if aorta ruptures. At that point blood products and a massive transfusion will be given(good IV's in these situations are life saving). Ensure you are coordinating with other healthcare teams to decide if the patient will be transferred or will be taking up for definite treatment ( essentially help expedite it).

Atrial Fibrillation with Rapid Ventricular Response (RVR)

In atrial fibrillation, the atria contract irregularly and rapidly, leading to poor ventricular filling. These rapid electrical signals pass to the ventricles, causing a fast and irregular ventricular rate. As a result, the heart pumps less efficiently, leading to decreased cardiac output due to both poor filling and rapid rate. Nursing Recognition: Suspect A-Fib with RVR when you see: • Irregularly irregular rhythm with a high heart rate on ECG • Hypotension • Palpitations • Chest discomfort • Shortness of breath Complications include: Thromboembolism → Stroke, Cardiomyopathy from persistent tachycardia, Hypotension from poor filling times→ Syncope Nursing Essentials: • Treat the underlying cause: Consider sepsis, acute coronary syndrome (ACS), hyperthyroidism, pulmonary embolism, etc. • Cardioversion considerations: o If onset is within 48 hours or patient is unstable o If onset is unclear: requires TEE (transesophageal echocardiogram) to rule out atrial clot unless patient is already on anticoagulation o Cardioversion for Afib RVR is typically not done as it comes with many risk factors. Typically in the ER, we are unable to obtain TEEs, and we most of the time, may not know a patients coagulation studies. So as a result, not typically done. • Treatment: o IV fluids: Unless contraindicated such as in CHF. o Medications used include Diltiazem, Metoprolol, Amiodarone, Esmolol, Magnesium, Digoxin o Consult cardiology early • Monitoring and Safety: o Obtain an ECG promptly o Repeat blood pressures frequently o Give medications slowly and cautiously o Ensure the patient has multiple IVs • Intravenous Diltiazem(Cardizem): o A calcium channel blocker used to lower heart rate. Used primarily IV in the ER with Atrial Fibrillation with a rapid ventricular response. At times, providers may also use it for SVT. o Dosing: 0.25mg/kg. Typically for adults most providers will just order around 20mg IV ▪ Usually followed by 30mg PO tablet to help control the heart rate longer. o Admin and Side Effects: Don't Push It. Give it slowly over two minutes. Cycle the bp right before it, during and after to ensure it did not drop a significant amount. ▪ If the BP is already low beforehand, do not give it until you talk to the provider about it. Perhaps start a liter of NS prior to administration of Diltiazem. If the BP is low, and you give it, it will only make it go lower. (They may tell you that the BP will go up after the heart rate comes down due to better filling of the ventricles and so forth but if the BP is already low beforehand, don't administer until the BP is addressed first). • Intravenous Metoprolol o A beta blocker used to lower heart rate. Typically used intravenously for atrial fibrillation with a rapid ventricular response. o Dosing: 2.5-5 mg slow IV. Can be repeated. If it works, typically followed by a PO dose of 50mg for longer heart rate control. o Side Effects ▪ Like with cardizem, do not administer if the BP is low, address the BP first. o Should not be used with patients who have asthma or COPD due to possibility of bronchoconstriction

Symptomatic Bradycardia

Mini Pathophysiology: A heart rate below 50 bpm (from sinus bradycardia, AV blocks, etc.) leads to decreased cardiac output. This results in hypoperfusion, which may present as: • Hypotension • Dizziness or lightheadedness • Altered mental status • Fatigue • Shortness of breath • Chest pain These symptoms arise due to inadequate perfusion of vital organs.

Nursing Essentials

• Initial Interventions: o IV access o Oxygen o Cardiac monitor o 12-lead ECG o Crash cart at bedside, prepare for transcutaneous pacing if indicated • Medications (based on cause and rhythm): o Atropine (first-line if applicable) o Epinephrine (if unresponsive to atropine) o Calcium gluconate (for suspected hyperkalemia or calcium channel blocker toxicity) o Glucagon and Zofran (for beta-blocker overdose) o High-dose Insulin and dextrose (for severe beta-blocker or calcium channel blocker toxicity) • Identify the Cause: o Is the patient on too much beta-blocker or calcium channel blocker? o Is it a 3rd-degree AV block? o Could this be digoxin toxicity?

Updated 2 Sep 2026