CLIND 1552 Week 7 Collapse (Thursday) PDF

CLIND 1552 – Week #7 – Collapse (Thursday) Syncope 1. 2. 3. 4. 5. Objectives Identify risk factors for vasovagal syncope Identify the risk factors for orthostatic hypotension List the various etiologies of cardiac-induced loss of consciousness Identify five differential diagnoses for syncope List...

CLIND 1552 – Week #7 – Collapse (Thursday) Syncope 1. 2. 3. 4. 5. Objectives Identify risk factors for vasovagal syncope Identify the risk factors for orthostatic hypotension List the various etiologies of cardiac-induced loss of consciousness Identify five differential diagnoses for syncope List common diagnostic tests to assist in determining the etiology of syncope Objective #1: Identify risk factors for vasovagal syncope Syncope • Greek “to cut short” • Clinical syndrome in which transient loss of consciousness (LOC) is usually caused by a period of decreased global cerebral blood flow • Presyncope/near-syncope: feeling but without LOC • Usually self-limiting, pulse still present NOTE: If a person suffers from a syncope but lacks a pulse, this is called cardiac arrest or sudden cardiac death. Cardiopulmonary resuscitation (CPR) MUST be started immediately. • • • • • • • • • • Syncope can look like seizures Both can have myoclonic jerking when unconscious Difference is that seizure disorder will have a postictal state upon awakening - Confusion, disorientation, numbness/weakness of limb affected - Can last for hours Any other syncope (vasovagal, orthostatic, etc.) should regain orientation within seconds to minutes Vasovagal Syncope (aka Reflex Syncope) Fainting because your body overreacts to certain triggers - Most common cause of syncope - Some stimulus causes a neural reflex - Characterized by bradycardia (+ Vagus nerve) and/or peripheral vasodilation (-sympathetic) - Benign, self-limiting (nothing is physically wrong with the person) Emotional: fear/phobias, pain (somatic or visceral) Situational: Micturition (urination), gastrointestinal stimulation (swallow, defecation), cough, sneeze, postexercise, others (eg, laughing, brass instrument playing, church) Orthostatic Hypotension (OH) Drop of blood pressure upon standing Blood pools to the legs due to gravity (when standing up) Normally, body will compensate by increasing sympathetic response, decrease parasympathetics: causes increase in heart rate, constricting blood vessels (to combat the effects of gravity) Causes of orthostatic hypotension - Drug-induced OH (most common cause of OH) o Blood pressure meds: vasodilators, diuretics o Antidepressants/SSRIs, nitrates, alcohol, narcotics - Volume depletion o Hemorrhage (less volume within vessels), diarrhea, vomiting - • • Autonomic failure (neurogenic OH – failure of the nerve circuit) o Diabetic neuropathy, Parkinson’s disease, Lewy body dementia, aging Cardiac Causes for Syncope Heart cannot pump enough blood to the brain Arrhythmia (bradycardia or tachycardia) - Bradycardia o Heart Rate less than 60 o Can cause lightheadedness and syncope o Example: AV blocks o Treatment: pacemaker (keeps the heart at a steady beat) NOTE: Bradycardia is more likely to cause syncope than tachycardia. - Tachycardia o Sinus tachycardia – physiologic response to exercise, fever, hypotension o Usually cannot exceed rate of >150 bpm through its normal pathways (diastole is not given enough time to fill up the ventricles) o Causes palpitations (unique to tachycardia), shortness of breath, lightheadedness, syncope o o o o o o Types of Tachycardia Atrial Fibrillation – many signals from the left atrium register through the AV node ▪ Irregularly irregular Atrial Flutter – similar presentation as atrial fibrillation but “saw-tooth” pattern on EKG; different etiology of disease AV Nodal Reentry Tachycardia (AVNRT) – an accessory pathway at the AV Node causes it to fire more frequently (supraventricular tachycardia) Atrioventricular Tachycardia (AVRT) ▪ Wolff-Parkinson-White syndrome (WPW) Ventricular Tachycardia – many signals come from the ventricles, stable/unstable Ventricular Fibrillation – ventricle quivers without effective pumping = DEAD! NOTE: Normal sinus rhythm is initiated by the sinoatrial (SA) node. NOTE: In atrial fibrillation, extra signals are coming from more places, other than the SA node, causing a quivering or irregular heartbeat (arrhythmia) that can lead to blood clots, stroke, heart failure, and other heart-related complications. NOTE: Wolff-Parkinson-White Syndrome, which is present at birth, involves an extra electrical pathway between the heart's upper and lower chambers, which causes a rapid heartbeat. WPW is rare, and the episodes of fast heartbeats usually are not life-threatening, although serious heart problems can occur. Bradycardia Atrial Fibrillation and Flutter • Normal Sinus Rhythm Sinus Tachycardia Wolff-Parkinson-White Syndrome Ventricular Fibrillation Pump Failure - Left Ventricle dependent: o Systolic heart failure o Diastolic heart failure o - Cardiomyopathy (congestive heart failure (CHF)) Other conditions affecting the pump system Pericardial Effusion – fluid in the pericardial sac o Cardiac tamponade – an emergency; the pericardial fluid compresses the heart including its chambers, causing inability to fill during diastole. Therefore, less blood is pumped out (decreased cardiac output) of the heart, causing syncope ▪ Beck’s triad: (1) jugular venous distension, (2) muffled heart sounds, (3) hypotension NOTE: Jugular venous distention (JVD) is caused by a narrowed superior vena cava. NOTE: The classic clinical scenario for aortic stenosis is a 50- to 60-year-old male passed out while shoveling snow. Normal Heart versus Congested (Weak-Walled) Heart • Normal Heart versus Hypertrophic Heart Cardiac Tamponade (Pericardial Effusion) Valvular - Aortic Stenosis: valve is stiff, blood can’t leave - Aortic Regurgitation: valve is floppy, blood comes back - Mitral Stenosis - Mitral Regurgitation Urinary Tract Infections (UTIs) • Young patients: Usually causes dysuria (pain or burning with urination) and increased urinary frequency • Elderly patients: - Altered mental status (AMS)/metabolic encephalopathy - Generalized weakness/collapse Objective #2: Identify the risk factors for orthostatic hypotension [Information included in Objective #1 under Orthostatic Hypotension] Objective #3: List the various etiologies of cardiac induced loss of consciousness [Information included in Objective #1] Objective #4: Identify five differential diagnoses for syncope [Information included in Objective #1] Objective #5: List common diagnostic tests to assist in determining the etiology of syncope Common Tests for Syncope • Bloodwork: Complete blood count (CBC), basic metabolic panel (BMP) - Complete Blood Count (CBC): RBCs, WBCs, platelets o Check for anemia due to blood loss - Basic Metabolic Panel (BMP): Na, K, Cl, HCO3, BUN, Cr, Glucose o Check for electrolyte abnormalities, dehydration, acute kidney injury • Orthostatic Blood Pressure Measurement 1. Lie down for 5 minutes 2. Check blood pressure/heart rate (BP/HR) 3. Sit-up for 1-2 minutes 4. Check BP/HR 5. Stand for 1-2 minutes 6. Check BP/HR - A drop in systolic blood pressure of ≥ 20 mm Hg, or a drop in diastolic blood pressure of ≥10 mm Hg, or a patient experiencing lightheadedness or dizziness is considered abnormal Heart rate normally increases with standing (~20 bpm increase), if heart rate is the same, can have autonomic dysfunction (problems with sympathetic nervous system) • EKG, monitor on telemetry - Use electrocardiogram (EKG) to check for arrhythmia, ischemia - Telemetry: continuous heart monitoring to evaluate for arrhythmia, can correlate with hospital symptoms • Echocardiogram - Ultrasound imaging of the heart - Can evaluate for pump failure, valvular disease, pericardial effusion Normal Heart Normal Heart (Labelled) Atrial Myxoma Severe Aortic Stenosis Heart Failure Tamponade NOTE: Atrial myxoma is a noncancerous tumor in the upper left or right side of the heart. It most often grows on the wall that separates the two sides of the heart, this wall is called the atrial septum. • Holter Monitor - Given to patients with frequent symptoms (eg. 2–3x a month) - Telemetry for home, continuous recording - Looking for arrhythmias - Usually records for a couple of days • Loop Recorder (for infrequent symptoms, obtains information and sends it to a control center) - Implantable device - Used for patients with infrequent symptoms (eg. less than once a month) - Can stay under the skin for over a year (embedded within the skin) • Tilt table test - Telemetry/continuous BP - Lay patient flat first - Tilt patient upward 70-80 degrees for 30 minutes – check symptoms - Give nitroglycerin – check symptoms - Symptoms + drop in BP = reflex syncope o Symptoms WITHOUT drop in BP = psychogenic pseudosyncope - Not reliable, not used much unless in small circumstances (where multiple workups are needed to find a source of the syncopal symptoms) o Recurring symptoms, thorough workup negative • CT head - Not typically needed in simple syncope workup - Done in ER workups frequently due to unwitnessed falls, unreliable history, concern for stroke - Rule out trauma from fall, bleeding, stroke, or other brain pathology o Strokes can cause collapse but do NOT cause syncope! Strokes will typically cause only one vessel to be ischemic. However, syncope does involve global cerebral ischemia. SOS Mr. Wright is a 70-year-old functionally independent male with poorly controlled systolic hypertension, hyperlipidemia, and osteoarthritis. He presents to his primary care office after having fallen while working in his yard 90 minutes previously. He states, “This is the first time anything like this has ever happened.” His fall was preceded by the abrupt onset of lightheadedness, numbness in his left hand, and vague visual disturbance with questionable loss of consciousness. After 10–15 minutes all symptoms were resolved, and he was able to get up unaided and has since felt fine. He is concerned about a stroke and if it would happen again while he was mowing his lawn or driving. Symptom – Organ System – Science – Practice 1. What is the most common cause of collapse? a. Cardiac syncope b. Cerebrovascular accident (CVA) c. Vasovagal syncope d. Seizure e. Pulmonary embolism 2. A 55-year-old man presents to the emergency department after he collapsed while shoveling snow. What is the most likely diagnosis to this very typical presentation? a. Aortic stenosis b. Myocardial infarction c. Vasovagal syncope d. Exacerbation of asthma e. Bacterial infection 1c. Vasovagal syncope 2a. Aortic stenosis