Diagnostic Imaging and EKG - Dr. Karly Turner, PDF

Diagnostic Imaging and Electrocardiograms Dr. Karly Turner PT, DPT Learning Objectives Describe the purpose, procedure, and clinical indications for common diagnostic imaging modalities Analyze EKG tracings to identify normal and abnormal rhythms and understand their clinical implica...

Diagnostic Imaging and Electrocardiograms Dr. Karly Turner PT, DPT Learning Objectives Describe the purpose, procedure, and clinical indications for common diagnostic imaging modalities Analyze EKG tracings to identify normal and abnormal rhythms and understand their clinical implications Integrate knowledge of diagnostic imaging and EKG findings to inform clinical decision making, assess patient readiness for physical therapy, and modify treatment plans based on results Outline Chest radiographs Electrocardiogram Doppler ultrasound Sinus Rhythm Irregular Rhythms Echocardiograms Escape Beats/Rhythms Transthoracic echocardiograms Premature Contractions Transesophageal echocardiogram Tachy-arrhythmias Computed Tomography scans Ischemia Computed Tomography Infarction Angiogram Pacemakers Ventilation/Perfusion Scan Pulmonary Function Tests Holter monitoring Chest Radiographs (Chest X-Ray) (CXR)1 Most common diagnostic examination to produce images of heart, lungs, airways, blood vessels, and the bones of the spine and chest Patient is usually standing in front of a plate Most common views are posteroanterior (PA) and lateral Patient is asked to take a few deep breaths and hold it “One view is no views” Radiodensity1 Air: black appearance Often seen in lungs, trachea, bowels Fat: dark gray appearance Often seen in thicker, adipose tissue Muscle, tendon, organ tissue: appears “neutral” or mid-gray Bone Cancellous or “spongy” bone appears light gray Cortical bone is white Contrast media: white Metal: white appearance Seen with jewelry, dental fillings, orthopedic hardware Systematic Assessment – For Reference2 Mnemonic Explanation Note A Airways Trachea should be central or slightly to the right. B Bones and Assess the bones visible in the image from top to bottom. The edges of the bones should be smooth, soft tissues otherwise may indicate a fracture. Also assess for bone density, edema, or metastatic lesion. C Cardiac On a PA image, the heart’s width should be less than 50% of the chest width. On an AP image, it should be between 50-60% of the chest width. D Diaphragm Right diaphragm is normally higher than the left. The costophrenic and cardiophrenic angles should be clearly visible. E Edges of the The edges of the heart should be clearly defined. Otherwise, there may be consolidation in the adjacent Heart lung lobes. F Fields and Check for any absence of normal lung markings in both fields. Also check for opaque masses, Fissure consolidation, or fluid. G Great Assess the aorta and pulmonary vessels. The aortic knob should be visible. A normal gastric bubble can be vessels or seen below the left diaphragm. Gastric bubbles H Hila The left hilum is normally higher than the right. Also check for masses or calcification around the hila. Normal CXR2 1. Trachea 2. Hilum (Hila) 3. Lungs 4. Diaphragm 5. Heart 6. Aortic knuckle/knob 7. Ribs 8. Scapulae 9. Breasts 10. Bowel gas What do you see? Date of Study: 9/20/2024 Indication: COPD exacerbation, shortness of breath, and increased cough. Comparison: CXR from 3/20/2024 Technique: Standard PA (posteroanterior) and lateral views of the chest were obtained. Findings: Lungs: Hyperinflation of the lungs is noted, with flattening of the diaphragms and increased retrosternal airspace. No focal airspace consolidation is seen. There is no evidence of acute pneumothorax or pleural effusion. The lung parenchyma demonstrates increased interstitial markings, consistent with chronic obstructive pulmonary disease (COPD). No new or worsening pulmonary infiltrates are identified compared to previous studies (if applicable). Mediastinum and Heart: The cardiomediastinal silhouette is narrowed, normal in configuration. The trachea remains midline, and there is no mediastinal widening. Hila: The hila are slightly prominent, consistent with chronic pulmonary changes, but without evidence of acute pathology such as lymphadenopathy or mass. Bones and Soft Tissues: The bony structures, including the ribs and spine, show no acute abnormalities. No evidence of acute bony fractures or lytic lesions. The soft tissues are unremarkable, with no subcutaneous emphysema or masses. Impression: Findings consistent with chronic obstructive pulmonary disease (COPD), including hyperinflation and flattened diaphragms. No evidence of acute cardiopulmonary abnormality such as pneumonia or pneumothorax. What do you see? Date of Study: 9/20/2024 Indication: History of heart failure Comparison: CXR 9/20/2023 Technique:  Standard PA (posteroanterior) and lateral views of the chest were obtained. Findings: Lungs:  The lungs demonstrate prominent interstitial markings, consistent with interstitial edema. No focal consolidation is observed.  There are no pleural effusions or pneumothorax identified. Pulmonary Vasculature:  Pulmonary vasculature appears prominent, particularly in the upper zones, consistent with pulmonary venous congestion. Mediastinum and Heart:  The cardiac silhouette is enlarged, indicating cardiomegaly. The cardiothoracic ratio is increased.  The trachea is midline, and there is no evidence of mediastinal widening. Hila:  The hila are slightly prominent, in keeping with the pulmonary vascular congestion, but there is no evidence of lymphadenopathy. Bones and Soft Tissues:  The bony thoracic structures are intact, with no fractures or other acute abnormalities.  The soft tissues are unremarkable, with no signs of subcutaneous emphysema or masses. Impression:  Cardiomegaly with prominent pulmonary vasculature and interstitial markings consistent with congestive cardiac failure. No evidence of consolidation or pleural effusion. Recommend clinical correlation and consideration of further evaluation for heart failure management. Doppler Ultrasound3 Noninvasive test used to measure the blood flow through vessels Bounces high-frequency sound waves off RBCs circulating in the blood stream Can estimate how fast blood flows by measuring the rate of change in frequency Types Doppler ultrasound: assesses how fast the blood flows Color doppler ultrasound: uses different colors to highlight different directions Examples4 Direct clot visualization Non compressible popliteal vein Color doppler showing reduced flow in great saphenous vein Echocardiograms5 Graphic outline of the heart’s movement Provider uses ultrasound from transducer placed on the chest to take pictures of the heart valves and chambers to evaluate the pumping action of the heart Techniques 2D ultrasound 3D ultrasound Transthoracic Echocardiogram vs Transesophageal Echocardiogram5 Transthoracic Echocardiogram (TTE) Transesophageal Echocardiogram (TEE) Transducer placed on outside of Takes pictures from inside the the chest chest with a small transducer Bouncing soundwaves “echos” down the throat into the appear as pictures that can be esophagus save for review Patients are sedated - may be unable to tolerate PT for a few hours 2D TTE Example with Color Doppler Impression: Mitral valve prolapse with mild to moderate mitral regurgitation Mild left atrial enlargement Normal left ventricular size and function Computed Tomography (CT) Scan6,7,8 Uses X-Rays and computed technology to create detailed cross- sectional images of the body Non-contrast CT: done when visibility would be sufficient for diagnosis, iodine allergy, or kidney problems Contrast-enhanced: iodine-based injection by IV Highlights blood vessels, organs Assists in diagnoses of tumors, vascular diseases, or inflammation Computed Tomography Aniography (CTA) Scan7 Used for arterial phase, push injection for faster rate Aorta Pulmonary arteries for PE For diagnosis of PE Sensitivity 96-100% Specificity 89-98% For diagnosis of CAD Sensitivity 97.2-100% Specificity 87.4-89% Ventilation/Perfusion (V/Q) Scan9,10 2 separate tests that can be done separately or together Perfusion scan: radioactive albumin is injected into the vein and machine scans your lungs as blood flows through them Ventilation scan: breathe in radioactive gas through a mask while sitting or lying down and then scanned Used when patients may not be able to tolerate high radiation dose Pregnancy Contrast dye allergy Renal insufficiency Pulmonary Function Tests (PFT)11,12 Shows how well the lungs are working Resource for predicting values based on age, gender, height: https://hankconsulting.com/RefCal.html Holter Monitoring13 Small, wearable device that records the heart’s rhythm over 1-2 days Indications: Used to spot irregular heartbeats that traditional electrocardiogram (ECG or EKG) hasn’t picked up Instructions: Continue normal activities Avoid getting monitor wet Wear throughout the full time period, even sleeping Electrocardiogram (EKG) Interpretation Standardized Method for ECG Interpretation 1. Rate 2. Rhythm 3. Axis Above Entry Level Knowledge 4. Hypertrophy 5. Infarction EKG Tracing Recording Overdrive Suppression Rapid automaticity (pacemaker activity) suppresses slower automaticity Heart’s “fail-safe” mechanism – ensures some level of organized contraction in the event of a pacemaker failure Junctional = AV junction Rate Determination of beats per minute Visual inspection or 6 second strip Typically, we are concerned with ventricular rate, so most often we will look for R waves Atrial rate can be counted as well Visual Inspection Method Find an R wave very close to a heavy red/black line The next heavy line is “300” Subsequent lines are 150, 100, 75, 60, 50 Rate is determined by where the next R wave lands, relative to the heavy lines following the “300” line Visual Inspection Method – How It Works Each “large” box (between each heavy line) is 0.2 seconds 5 complete, large boxes in one second Count number of boxes between each QRS complex to determine time (in seconds) between each contraction Divide that number (in seconds) into 60 to determine rate 6 Second Strip Preferred method for irregular rhythms AND bradycardic rhythms (< 60 bpm) Count the number of complexes in 6 second strip and multiply by 10 R waves that land on the beginning or end line DON’T COUNT 6 second strip = 30 large boxes Some have ‘tick marks’ Rhythm Check for: P wave before every QRS QRS after every P wave Determine P-R interval (normal is less than or equal to 0.2 seconds) QRS interval (normal is 0.12 seconds or less) Normal Sinus Rhythm Sinus Bradycardia Sinus Tachycardia Sinus Arrhythmia Normal variation known as heart rate variability (HRV) Normal variability in heart rate (HR) regularity due to inspiration/expiration cycle Constant minor changes in sympathetic and parasympathetic input Absence of this variability is ominous Causes could include stress, concussion, sleep disorders, chronic medical conditions Dysrhythmia = Arrhythmia Irregular Rhythms Tachy-arrhythmias Atrial fibrillation Paroxysmal tachycardia Atrial fibrillation with rapid ventricular Atrial rate Ventricular Ventricular fibrillation Flutter Escape Beats/Rhythms Fibrillation Sinus pause Ischemia Atrial escape Infarction Junctional escape Ventricular escape Pacemakers Premature Contractions Premature atrial contraction Premature junctional contraction Premature ventricular contraction Atrial Fibrillation (Afib) No obvious P waves Looks like a squiggle where the P waves should be Atrial Fibrillation with Rapid Ventricular Rate (Afib with RVR) Most common dysrhythmia that brings people to the hospital Afib with rate > 100 bpm Cardiac output (CO) can be reduced by more than 25% leading to eventual heart failure (HF) Sluggish movement of blood can form blood clots and they can embolize and cause stroke Ventricular Fibrillation (Vfib) Rate > 350 bpm MEDICAL EMERGENCY! Rhythm is irregular Patient will likely be Absent/no discernable P waves unconscious, pulseless, and apneic (not breathing) QRS complex is “wide and weird” Requires immediate medical treatment including CPR and DEFIBRILLATION Escape Escape beat: An automaticity focus transiently escapes overdrive suppression to emit one beat Atrial escape beat Junctional escape beat Ventricular escape beat  Sinus Pause/Arrest Cessation of impulse generation of the SA node Pause: transient cessation (also called a “sinus block” Arrest: longer lasting cessation When the SA node does not fire, an impulse is generated by another automaticity focus (the next fastest in line) in the overdrive suppression cascade If pause is less than 3 seconds, probably not something to worry about Atrial Escape Sinus node didn’t pick back up, so atrial foci did Can tell due to different looking P wave and beat is slightly lower Atrial Escape Beat – SA node picks back up Atrial Escape Rhythm: SA node didn’t pick back up – this is concerning Junctional Escape Junctional foci: when ventricles contract after a pause Will still have a narrow QRS complex Missing atrial contraction, but can live with a junctional rhythm Resting HR will be between 40-60 bpm Junctional Escape Beat Junctional Escape Rhythm Ventricular Escape Ventricular foci, contraction is less organized HR will be low, between 20-40 bpm QRS complex is wide and weird Ventricular Escape Beat Ventricular Escape Rhythm Premature Contractions An irritable focus spontaneously fires a single stimulus BEFORE the next “normal” depolarization begins Premature Atrial Contraction (PAC) Premature Junctional Contraction (PJC) Premature Ventricular Contraction (PVC) Name is determined by source of beat Premature Atrial Contraction (PAC) Atrial Bigeminy and Trigeminy Bigeminy: irritable focus fires every other “normal” beat Trigeminy: irritable focus fires after every two “normal” beats Quadrigeminy: every 4th beat is an abnormal beat Premature Junctional Contraction (PJC) Note the “early” appearance of the complex and lack of a P wave Can occur with bigeminy, trigeminy, quadrigeminy Premature Ventricular Contraction (PVC) P wave: absent for that contraction P-R interval: N/A QRS complex: “wide and weird” Can occur as bigeminy, trigeminy, quadrigeminy May occur as couplets or triplets (2-3 PVCs in a row) Clinical Implications of PVCs PVCs are more concerning when: There are more than 6 per minute The number increases with activity The morphology diversifies with activity The patient becomes increasingly symptomatic (signs and symptoms of poor perfusion) More concerning when they’re newer – like first time it happens is when you are in the room and they had no prior knowledge of it Less concerning when: Disappearance or decrease with activity No change with activity Asymptomatic Premature Contraction vs Escape Beat Question: But they look the same… how do I know which one it is? Answer: Look at the timing Escape beat occurs after when you would expect the next normal heart beat to occur Premature beat occurs before when you would expect the next normal heart beat to occur Tachy-arrhythmias Paroxysmal tachycardia: suddenly irritable focus (atrial, junctional, or ventricular) begins rapidly pacing. Rhythm is usually regular One irritable focus so each complex will look the same Flutter: suddenly irritable focus (atrial or ventricular) begins rapid pacing at 250-350 bpm Each complex will look nearly the same Rhythm is usually regular Fibrillation: sudden discharge of MULTIPLE foci (atrial or ventricular) pacing at rate > 350 bpm Each complex will look different due to multiple different foci Likely irregular rhythm 150-250 BPM 250-350 BPM 350 + BPM Paroxysmal Tachycardia Flutter Fibrillation Causes of Paroxysmal Tachycardia Atrial and junctional tachy-arrhythmias are usually due to epinephrine or other chemical stimulants Ventricular tachy-arrhythmias are usually due to hypoxia, hypokalemia, or other “threatening” physiological processes Paroxysmal Atrial Tachycardia (PAT) AKA Supraventricular Tachycardia (SVT) Normal P wave, QRS complex, PR interval Clinical significance – similar to sudden onset afib with RVR Paroxysmal Ventricular Tachycardia (V-tach) May occur as “runs” of V-tach which spontaneously stop and start Rate 150-250 bpm, regular rhythm, no discernible P waves Ominous finding: Even if patient is asymptomatic, stop treatment, ensure patient is safe, and notify medical team Atrial Flutter Originates in one irritable atrial focus Atrial rate is 250-350 bpm May or may not precipitate ventricular rhythm > 100 bpm Usually occurs in a 2:1, 3:1, or 4:1 ratio of flutter waves (P waves : QRS complexes) Ventricular Flutter Single ventricular focus firing at a rate of 250-350 bpm Fast rate makes proper diastolic filling impossible, and thus this rhythm rapidly decays into a lethal dysrhythmia No discernible P waves Rhythm is regular MEDICAL EMERGENCY: clinically the same as V-Tach or V-fib Torsades de Pointes (Torsades) “Twisting of points” Likely represents two competitive, irritable ventricular foci Rate is 250-350 bpm Causes: hypomagnesemia, hypokalemia, Long QT syndrome Sometimes can resolve spontaneously, never should be assumed insignificant MEDICAL EMERGENCY: Treated the same as V-Tach, V-flutter, V-fib Ventricular Fibrillation Rate > 350 bpm Rhythm is irregular Absent/no discernible P waves QRS complex is wide and weird MEDICAL EMERGENCY – Requires immediate medical treatment including CPR and DEFIBRILLATIOM Patient is likely unconscious, pulseless, and apneic Ischemia Lack of blood flow – not cell death yet On EKG, may be represented by inverted T waves or possibly ST segment depression Clinically significant if more than 2 mm (Acute) Infarction Indicated by ST segment elevation in the leads (II, III, aVF) which “capture” the portion of the heart suffering from the infarction (Chronic) Infarction Q waves which indicate presence of necrotic heart tissue are: At least 0.04 seconds long > 25% the height of the QRS amplitude > 2 mm deep Seen in V1-V3 Cardiac Arrest NOT shockable rhythms, there’s nothing to “reset” – keep performing CPR Asystole Functionally no heartbeats that produce a pulse, PEA can look organized Patient is clinically “dead”, can technically be revived Pulseless Electrical Activity (PEA) Artificial Pacemakers May provide atrial or ventricular pacing, or both Will display as “pacer spikes” on ECG References 1. 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