EMS Cardiac Emergencies - Pericarditis

Overview

Pericarditis is the inflammation of the pericardium, the protective sac around the heart. For EMS providers, recognizing pericarditis is critical because it can lead to serious complications like pericardial effusion or cardiac tamponade. 

The condition can be caused by a range of factors, including viral infections, bacterial infections, autoimmune disorders like lupus, trauma, and certain medications. 

It may also occur after a myocardial infarction (post-MI pericarditis or Dressler's Syndrome) or be associated with cancer or renal failure. Understanding the causes can help guide treatment and determine how urgent the patient’s condition may be.

Here are some things an EMS Provider needs to know:

Signs and Symptoms

Patients with pericarditis typically present with chest pain that is sharp, stabbing, and pleuritic in nature, meaning it worsens with deep breaths or coughing. A distinguishing feature of pericarditis-related chest pain is that it often improves when the patient sits up and leans forward, and worsens when lying flat. The pain can radiate to the neck, shoulders, or back, which can sometimes mimic the pain of a myocardial infarction.

In addition to chest pain, fever may be present, especially in cases caused by infections. Patients might also experience dyspnea, particularly if pericardial effusion (fluid buildup around the heart) develops. 

A classic sign detectable on physical examination is a pericardial friction rub, a scratchy or grating sound heard with a stethoscope near the left sternal border. 

EMS Providers may notice widespread ST-segment elevation across multiple leads and PR-segment depression on an EKG, both of which are characteristic of pericarditis. 

These combined symptoms can help differentiate pericarditis from other cardiac conditions, such as myocardial infarction.

Prehospital Treatment

Prehospital care for pericarditis focuses on symptom management and preventing complications. Positioning the patient in an upright or leaning-forward posture can relieve pain, and oxygen should be administered if hypoxia or dyspnea is present. 

NSAIDs, such as aspirin, if within protocol, can be used to alleviate pain and reduce inflammation. 

EKG monitoring is essential to detect any potential changes, such as arrhythmias or signs of tamponade. 

Providers should establish IV access for medications or fluid resuscitation, and if cardiac tamponade is suspected (marked by hypotension, jugular venous distention, and muffled heart sounds a.k.a Beck's Triad), rapid transport to a hospital is critical. 

Early hospital notification can prepare the receiving facility for advanced care.

In-Hospital Treatment

Once in the hospital, patients with pericarditis will undergo diagnostic testing, including an EKG to assess for pericardial effusion, and other tests such as chest X-rays or bloodwork to identify the underlying cause. 

Treatment usually involves anti-inflammatory medications like NSAIDs or colchicine to reduce inflammation and prevent recurrence. In some cases, corticosteroids may be used, but they are typically reserved for autoimmune cases or refractory pericarditis. 

Antibiotics are administered if a bacterial infection is identified. If a large pericardial effusion or cardiac tamponade is detected, emergency pericardiocentesis (draining fluid from the pericardium) is necessary. 

For recurrent or chronic pericarditis, surgical intervention, such as a pericardiectomy, might be considered.

Key Takeaways for EMS Providers

EMS Providers should be able to recognize pericarditis through its hallmark symptoms, including sharp, pleuritic chest pain and characteristic ECG changes. 

Rapid identification and intervention can prevent complications such as cardiac tamponade.

Prehospital care should focus on pain management, patient positioning, and continuous cardiac monitoring, while maintaining a high index of suspicion for worsening conditions. 

Prompt transport to a facility equipped for advanced cardiac care is essential, where definitive treatments, such as anti-inflammatory medications or pericardiocentesis, can be administered. Early intervention and effective prehospital management play a key role in patient outcomes.

Further Reading:

Ari D. Leib; Lisa A. Foris; Tran Nguyen; Karam Khaddour (2023) Dressler Syndrome. Treasure Island, Florida: StatPearls Publishing  Accessed September 7, 2024

Bledsoe, B. E., Cherry, R. A. & Porter, R. S (2023) Paramedic Care: Principles and Practice (6th Ed) Boston, Massachusetts: Pearson.

Peate, I. & Sawyer, S (2024) Fundamentals of Applied Pathophysiology for Paramedics. Hoboken, New Jersey: Wiley Blackwell.

Xanthopoulos, A. & Skoularigis, J. (2017) Diagnosis of Acute Pericarditis. Journal of Cardiology Practice #15. Accessed September 6, 2024

EMS Cardiology - EKG Rhythms

EMS providers play a crucial role in identifying and managing various cardiac rhythms in the prehospital setting.

An EKG (electrocardiogram) rhythm refers to the pattern of electrical activity in the heart as recorded by an electrocardiogram.

An electrocardiogram is a medical test that measures the electrical impulses generated by the heart during each heartbeat.

It is commonly used to diagnose and monitor various heart conditions. Understanding the components of an EKG rhythm is essential for accurate interpretation.

The EKG rhythm is graphically represented on paper or a monitor, illustrating the different phases of the cardiac cycle.

The typical EKG waveform includes P waves, QRS complexes, and T waves, which correspond to specific electrical events in the heart.

Here are the key components and some common abnormal rhythms:

Key Components of EKG Rhythm:

P Waves:

Normal: Represents atrial depolarization (contraction).

Shape: Typically upright and rounded.

Duration: Normally 0.06 to 0.12 seconds.

Abnormalities: Absent P waves, inverted P waves, or abnormal shapes may indicate atrial issues.

QRS Complex:

Normal: Indicates ventricular depolarization (contraction).

Shape: Typically narrow (0.06 to 0.10 seconds).

Duration: Abnormally wide QRS complexes may indicate ventricular conduction abnormalities.

Abnormalities: Wide QRS (e.g., bundle branch blocks) or absence of QRS (asystole) are concerning findings.

T Waves:

Normal: Represents ventricular repolarization (relaxation).

Shape: Usually upright and rounded.

Abnormalities: Inverted T waves or changes in T-wave morphology may indicate ischemia, electrolyte imbalances, or other cardiac issues.

PR Interval:

Normal: Represents the time from atrial depolarization to ventricular depolarization.

Duration: Normal PR interval is 0.12 to 0.20 seconds.

Abnormalities: Prolonged PR interval may indicate heart block.

QT Interval:

Normal: Represents the total time for ventricular depolarization and repolarization.

Duration: Corrected QT interval (QTc) is influenced by heart rate.

Abnormalities: Prolonged QT interval may predispose to ventricular arrhythmias.

Heart Rate:

Normal: Adult resting heart rate is 60 to 100 beats per minute.

Abnormalities: Tachycardia (heart rate >100 bpm) or bradycardia (heart rate <60 bpm) may indicate various cardiac conditions.

The pattern and timing of these waves help healthcare professionals assess the heart's electrical activity and identify any abnormalities in the rhythm.

Normal EKG rhythms provide information about the regular and coordinated functioning of the heart, while abnormal rhythms, such as atrial fibrillation, ventricular tachycardia, or bradycardia, can indicate various heart conditions.

Common Abnormal Rhythms:

Atrial Fibrillation (AFib):

Irregularly irregular rhythm.

Absence of distinct P waves.

Chaotic, fibrillatory baseline.

Atrial Flutter:

Regular or irregular rhythm with sawtooth-shaped P waves.

Atrial rate is often faster than the ventricular rate.

Ventricular Tachycardia (VTach):

Regular, wide QRS complexes (>0.12 seconds).

Often associated with hemodynamic instability.

Ventricular Fibrillation (VFib):

Chaotic, irregular waveform with no organized QRS complexes.

Emergency situation requiring immediate defibrillation.

Supraventricular Tachycardia (SVT):

Narrow QRS complexes with a rapid heart rate.

Regular or slightly irregular rhythm.

Asystole:

Absence of any discernible electrical activity.

Considered a medical emergency requiring CPR and advanced life support interventions.

Bradycardia:

Heart rate <60 bpm

May be associated with heart blocks or intrinsic conduction system issues.

Clinical Considerations:

Ischemia: ST-segment elevation or depression may indicate myocardial ischemia.

Conduction Blocks: Bundle branch blocks or heart blocks may affect the QRS complex and PR interval.

Medication Effects: Some medications can affect the EKG, leading to QT prolongation or other abnormalities.

EMS providers should receive regular training in EKG interpretation to enhance their ability to recognize and respond to abnormal rhythms promptly.

Additionally, collaboration with medical control and receiving hospitals is essential for optimal patient care in the prehospital setting.

Further Reading:

Garcia, T. (2013) 12-Lead ECG: The Art of Interpretation (2nd Ed.) Jones & Bartlett Learning

Walraven, G. (2016) Basic Arrhythmias (8th Ed.). Pearson 

ECG Educational Standards for Prehospital Providers

https://www.jems.com/patient-care/cardiac-resuscitation/ecg-educational-standards-for-prehospital-providers/ Accessed January 22, 2024

EMS Cardiology - Einthoven's Triangle

Einthoven's Triangle is a concept in electrocardiography that refers to the arrangement of three limb leads used to record the electrical activity of the heart.

It was developed in 1912 by Willem Einthoven, a Dutch physiologist, and forms the basis for the standard 12-lead electrocardiogram (ECG / EKG) used in clinical and prehospital settings today.

Understanding Einthoven's Triangle is relevant to EMS providers as it aids in the proper placement of leads and the interpretation of EKGs.

Einthoven's Triangle Basics: Components & Formation

Einthoven's Triangle consists of three limb leads, labeled I, II, and III, forming an inverted equilateral triangle with the heart at the center.

The triangle represents the spatial orientation of the heart's electrical axis, and is the basis for correct lead placement on a patient.

The axis is crucial in diagnosing heart conditions and understanding the overall electrical orientation of the heart.

Each lead measures the heart’s electrical field during the depolarization and repolarization of myocytes (muscle cells).

This electric field is represented as a vector that continuously changes and can be measured by recording the voltage, or potential, difference between electrodes.

Lead I: Measures the potential difference between the right and left arms, where the right electrode is negative, and the left is positive.

Lead II: Measures the potential difference between the right arm and left leg, where the right electrode is negative, and the left leg is positive.

Lead III: Measures the potential difference between the left arm and left leg, with the left arm electrode negative and the left leg positive.

The potential difference reflects the electrical contrast between distinct points. Within the context of Einthoven's Triangle, this concept relates to capturing the heart's electrical activity from varied spatial perspectives. It is integral to the creation of an electrocardiogram (ECG or EKG) and facilitates the interpretation of cardiac rhythms.12-Lead EKG:

Recognition of Abnormalities:

Understanding the spatial relationship of leads can assist EMS providers in recognizing abnormalities such as axis deviations and changes in amplitude and direction of the EKG waveforms.

Clinical implications & Decision-Making:

Proper EKG interpretation based on Einthoven's Triangle can help EMS providers in making timely clinical decisions, especially in the identification of acute myocardial infarctions and arrhythmias.

Myocardial Infarction: Changes in specific leads (such as ST-segment elevation or depression) can indicate myocardial infarction and guide the urgency of interventions.

Arrhythmias: The configuration of waveforms in Einthoven's Triangle aids in the identification of various arrhythmias, influencing treatment decisions.

Summary:

Einthoven's Triangle is a fundamental concept in electrocardiography that EMS providers need to understand for accurate EKG interpretation.

It offers a spatial orientation of leads, assisting in lead placement, axis determination, and the identification of cardiac abnormalities.

Although Einthoven's Triangle involves just three leads, it serves as the basis for the 12-lead EKG, which offers a more comprehensive view of the heart's electrical activity. This expanded perspective aids in diagnosing various cardiac conditions.

This knowledge is indispensable for EMS providers in the prehospital setting, enabling them to make informed decisions and deliver timely care to patients with cardiac issues.

Further Reading:

Garcia, T. (2013) 12-Lead ECG: The Art of Interpretation (2nd Ed.) Jones & Bartlett Learning

Walraven, G. (2016) Basic Arrhythmias (8th Ed.). Pearson

ECG Educational Standards for Prehospital Providers

Medical Device History: Einthoven’s Triangle and the Electrocardiogram

EMS Cardiology - Electrocardiograms (EKGs)

EMS Providers play a crucial role in assessing and managing patients in prehospital settings.

Understanding electrocardiograms (EKGs) is vital for EMS providers as it allows them to quickly assess and identify cardiac issues in patients.

Here's a breakdown of what EMS providers should know about EKGs, including their history, development, and use in the prehospital setting:

Definition:

An electrocardiogram (EKG or ECG) is a graphic representation of the electrical activity of the heart over time.

It is commonly used to diagnose various heart conditions and monitor the effectiveness of treatments.

History of Development:

The development of the EKG can be attributed to several key figures, including Willem Einthoven, who invented the first practical EKG in the early 20th century.

Einthoven's string galvanometer allowed for the recording of electrical potentials produced by the heart.

Components of an EKG:

P Waves: Represent atrial depolarization.

QRS Complex: Indicates ventricular depolarization.

T Waves: Represent ventricular repolarization.

Use in Prehospital Setting:

Early Identification of Cardiac Issues:

EKGs help identify cardiac abnormalities, such as myocardial infarction (heart attack), arrhythmias, and conduction disturbances.

Early identification allows for timely intervention and improves patient outcomes.

Integration with Cardiac Monitoring:

Portable EKG monitors are part of EMS equipment, allowing continuous cardiac monitoring during patient transport.

Monitoring changes in the EKG pattern helps in assessing the patient's response to treatment and detecting new issues.

Communication with Receiving Hospitals:

Transmitting EKG data to receiving hospitals allows for early notification and preparation for cardiac patients.

This is particularly important for patients requiring immediate interventions, such as percutaneous coronary intervention (PCI).

Training and Proficiency:

EMS providers should receive training in EKG interpretation to accurately identify abnormalities.

Proficiency in recognizing ST-segment elevation, T-wave changes, and arrhythmias is crucial for making rapid clinical decisions.

Clinical Decision Support:

EKG findings guide clinical decision-making, such as the administration of thrombolytics or antiplatelet agents for acute coronary syndromes.

Recording and Documentation:

Accurate documentation of EKG findings is essential for the continuity of care.

Clear communication of findings to hospital staff helps streamline the transition of care.

Continuous Quality Improvement:

EMS agencies should establish protocols for the ongoing review and quality improvement of EKG interpretations.

Regular training sessions and case reviews contribute to improved proficiency among EMS providers.

In summary, EMS providers should have a solid understanding of EKG basics, historical development, and the practical application of EKGs in the prehospital setting.

This knowledge enhances their ability to rapidly assess and manage patients with cardiac conditions, ultimately improving patient outcomes.

Ongoing education and proficiency maintenance are crucial in this dynamic field.

Further Reading:

Garcia, T. (2013) 12-Lead ECG: The Art of Interpretation (2nd Ed.) Jones & Bartlett Learning

Walraven, G. (2016) Basic Arrhythmias (8th Ed.). Pearson

ECG Educational Standards for Prehospital Providers