How Can I Tell What Block It Is?

Helpful Tips for AV BlocksSecond degree Type IThink Type I drops oneWenckebach winks when it drops oneSecond degree Type IIThink 2:1 (knowing it can have variable block like 3:1, etc.) Third degree - completeThink completely no relationship between atria and ventricles

*Implanted PacemakerMost set on demandWhen the heart rate falls below a preset rate, the heart demands the pacemaker to take over

Paced Rhythm - 100% Capture

Goal of TherapyIs rate too slow? Speed it up (Atropine, TCP)Is rate too fast? Slow it down (Vagal maneuvers, Adenosine, Verapamil)Blood pressure too low? Is there enough fluid (blood) in the tank?Improve contractility of the heart (dopamine, Epinephrine)Are the ventricles irritable?Soothe with antidysrhythmic (Amiodarone, Lidocaine)

Treatments for RhythmsAs always treat the patient NOT the monitorObtain baseline vitals before and/or during ECG monitoringIdentify rhythm and determine corresponding SOP to followHelpful to have at least one more person verify stripObtain patient history & OPQRST of current complaint

Transcutaneous PacingNo response to doses of atropineUnstable patient with a wide QRS Set pacing at a rate of 80 beats per minute in the demand modeStart output (mA) at lowest setting possible (0) and increase until capture notedSpike followed by QRS complexConsider medications to help with the chest discomfort

TachycardiasCan be generally well tolerated rhythmsORCan become lethal usually related to the heart rate and influence on cardiac outputAsk 2 questions:Is the patient stable or unstable?If unstable, needs cardioversionIf stable, determine if the QRS is narrow or wideQRS width drives decisions for therapy in stable patient

12-lead ECG ReviewLead placementLead II monitoringObtaining 12 lead EKGLead / location correlation of ST elevationST elevation criteria 12 lead practice EKGs

12 Lead & Monitoring Lead PlacementEinthovens TriangleArm and Leg leads

Chest leads (V leads)

Where do those chest stickers go?Make sure to feel for intercostal space dont just use your eyes!

and the FEMALESBras loosened, people, if in your wayNot all nipple lines are created equalCover the chest with a towel/sheet after leads are placed to preserve modesty

Lead Placement in the FemaleAvoid placing electrodes on top of breast tissueUse the back of the hand to displace breast tissue out of the way to place electrodeAvoids perception of gropingCan ask the patient to move left breast out of way.

Lead PlacementThe more accurate the lead placement, the more accurate the 12-lead interpretation12-leads are often evaluated on a sequential basis, each interpretation considering the previous oneV4 - V6 should be in a gentle upward curve following the same 5th intercostal rib spaceCMC has done many trainingsWe should be doing this right by nowPlacement was standardized in 1938; this is proven science and placement must be accurate!

Heart & 12 Lead StripCorrelation

12 Lead StripsRemember: Every lead is like a camera angle

12 Lead Strips cont.Imagine your strips broken into groups like thisIIIIIIaVLaVFV1V2V3V4V5V6aVR

RememberYou will see Lead II first!This is how you monitor patients rhythmsMay see reciprocal changes as ST depression

Value of Reciprocal Changes*ST elevation means acute transmural injury injury across all 3 layers of the heart muscleDiagnosis often based on:Presence of ST elevation in 2 or more contiguous leadsReciprocal changes*Confirms acute-injury patternsPatient historyPresentation

12 Lead Comparison Chart for Reciprocal Change(Main ones are highlighted)

Contiguous ECG LeadsEKG changes are significant when they are seen in at least two contiguous leads

Two leads are contiguous if they look at the same area of the heart or they are numerically consecutive chest leads

ST Elevation EvaluationLocate the J-pointIdentify/estimate where the isoelectric line is noted to beCheck the standardized 2mm mark at the far left or beginning of each row of the EKG stripCompare the level of the ST segment 0.4 seconds after the J point to the isoelectric lineElevation (or depression) is significant if more than 1 mm (one small box) is seen in 2 or more leads facing the same anatomical area of the heart (ie: contiguous leads)

Measuring for ST ElevationFind the J pointIs the ST segment >1mm above the isoelectric line in 2 or more contiguous leads?

Complications of Lateral Wall MI I, aVL, V5, V6

Monitor for lethal heart blocksSecond degree type II classicalThird degree heart block completeTreat with TCPConsider sedation for patient comfortMonitor for captureMonitor for improvement by measuring level of consciousness and blood pressure

Complications of Inferior Wall MIII, III, aVFMay see Mobitz type I WenckebachDue to parasympathetic stimulation & not injury to conduction systemHypotensionRight ventricle may lose some pumping abilityVenous return exceeds output, blood accumulates in right ventricleLess blood being pumped to lungs to left ventricle and out to bodyDevelop hypotension, JVD, with clear lung soundsTreated with additional fluid administered cautiouslyContact Medical Control prior to NTG administration

Complications of Septal Wall MIV1 & V2Monitor for lethal heart blocksSecond degree type II classicalThird degree heart block completeTreat with TCPRare to have a septal wall MI aloneOften associated with anterior and/or lateral wall involvement

Complications of Anterior Wall MIV3 & V4Occlusion of left main coronary artery the widow makerCardiogenic shock and death without prompt reperfusionSecond degree AV block type IIOften symptomaticOften progress to 3rd degree heart blockPrepare to initiate TCPThird degree heart block completeRhythm usually unstableRate usually less than 40 beats per minutePrepare to initiate TCP

Acute Coronary SyndromeStablePatient AlertSkin warm and drySystolic BP>100 mmHgAspirin 324 mg by mouth

Nitroglycerine 0.4 mg SLMay be repeated every 5 minIf pain persists following 2 doses, advance to Morphine Sulfate Morphine Sulfate 2mg IVPSlowly over 2 minutesMay repeat every 2 minutes as needed, to a maximum total dose of 10 mgTransportUnstableAltered Mental StatusSystolic BP< 100 mmHgAspirin 324 mg by mouth, if pt can tolerateContact Medical controlMonitor and Transport

Note: ASPIRIN my be withheld if patient is reliable and states has taken within 24 hoursRoutine Medical Care 12 Lead ECG and transmit, if available

Patient Presenting with Coronary Chest Pain AMI Until Proven OtherwiseOxygenMay limit ischemic injuryNew trends/guidelines coming out in 2011 SOPsAspirin - 324 mg chewed (PO)Blocks platelet aggregation (clumping) to keep clot from getting biggerChewing breaks medication down faster & allows for quicker absorptionHold if patient allergic or for a reliable patient that states they have taken aspirin within last 24 hours

Nitroglycerin - 0.4 mg SL every 5 minutesDilates coronary vessels to relieve vasospamsIncreases collateral blood flowDilates veins to reduce preload to reduce workload of heartWatch for hypotensionIf inferior wall MI (II, III, aVF), contact Medical Control prior to administrationIf pain persists after 2 doses, move to MorphineCheck for recent male enhancement drug use (ie: viagra, cialis, levitra)Side effect could be lethal hypotension

Acute Coronary SyndromeMedications cont.

Acute Coronary SyndromeMedications cont.Morphine - 2 mg slow IVPDecreases pain & apprehensionMild venodilator & arterial dilator Reduces preload and afterloadGiven if pain level not changed after the 2nd dose of nitroglycerinGive 2mg slow IVP repeated every 2 minutes as neededMax total dose 10 mg

Practice RhythmsBreak into groups of 2 or 3 for rhythm quizzingInstructor will use wristwatch or stopwatch to give each group 30 seconds to determine stripYou dont have 5 min in the field, you dont get 5 min in the classroomMessage to Instructor:Refer to slide notes for more information

Sinus w/ 1st degree BlockNo symptoms are due to the first degree heart block; symptoms would be related to the underlying rhythm

Junctional TachycardiaNote: Inverted P waves; heart rate 140

How is the patient tolerating the heart rate?

2nd Degree Type 1 WenckebachPR getting longer and finally 1 QRS drops; patient generally asymptomatic; can be normal rhythm for some patients

WPW SyndromeSlurring at beginning of QRS (delta wave)Better diagnosed on 12 lead EKG; patient asymptomatic unless heart rate becomes tachycardic

2nd Degree Type II (2:1 conduction)Should be preparing the TCP for this patient

3rd degree heart block (complete)with narrow QRSSymptoms usually based on overall heart rate the slower the heart rate the more symptomatic the patient. Prepare the TCP.

NSR to Torsade des PointesIf torsades is long lasting, patient may become unresponsive and arrest. Prepare for defibrillation followed immediately with CPR

Intermittent 2nd Degree Type II(Long PR intervals; periodic dropped beat)Consider need to apply TCP and then turn on if patient symptomatic

Why would this patient have symptoms of a stroke?Atrial fibrillation puts patient at risk from clots in the atria breaking loose and lodging in a vessel in the brain

Rhythm irregularly irregularPatient most likely on Coumadin and digoxin

Ventricular TachycardiaWhat 2 questions should you ask for all tachycardias?Is the patient stable or unstable?If stable, then you have time to determine if the QRS is narrow or wideWhats this strip?

Paroxysmal Supraventricular Tachycardia (PSVT) into sinus rhythmEvidence of abrupt stopping of the SVT

Sinus ArrhythmiaCommon in the pediatric patient and influenced by respirations. Treatment is not indicated

Sinus with unifocal PVCsin trigeminyOften PVCs go away after administration of oxygen

Multifocal Atrial Tachycardia(MAT)Rapid Wandering PacemakerIdentification can be SVT and treatment would be based on patient symptoms

12 Lead Time!Same as Lead II stripsIdentify St elevation and try to give anatomical locationsRemember to be watchful for typical complications based on location of infarct and blocked coronary vessel

ST elevation in V2 V5(Anterior wall)

No ST elevation but peaked T waves (Hyperkalemia)

HyperkalemiaCan be caused byOver medication of potassium supplement (ex. K-dur)Excessive intake of foods (bananas are high in potassium)Crush syndromeAfter pressure/crush is released, the heart is hit with the potassium that built-up in the poorly perfused crushed areaToo much potassium can lead to critical heart dysrhythmias; difficult to treatOther populations at riskDialysis patientPatient in diabetic ketoacidosis

ST elevation in II, III & aVF(Inferior wall with LBBB)Watch for hypotension

ST ElevationInferior Wall II, III, aVFWatch for hypotension

ST elevation in II, III, aVF(Inferior wall - note reciprocal changes)Watch for hypotension

ST elevation in V1 V6, I & aVL(Anteroseptal with lateral extension)Extensive anteroseptalWatch for heart block

ST elevation V2-V5Watch for heart block

DocumentationRhythm strip interpretationIf 12 lead EKG obtained:Note presence or absence of ST elevationIf ST elevation noted, in which leadsIf EKG was transmitted to hospital

Hospital NotificationNotify the receiving hospital as soon as possible about a cardiac alertHow did you determine this may be a cardiac alert?Your general impression was made based on:Gathering patient historyPerforming a cardiac assessmentObtaining a 12 lead EKG as quickly as possible after first patient contact12 lead EKG evaluated for presence of ST elevation

Field TripIf your department can obtain 12 lead EKGs review the process for marking Patient age and raceYour department name on the 12 leadIf your department can fax, review the processGo to the ambulance to review the equipment and process

Questions?

BibliographyAtwood, S., Stanton, C., Storey-Davenport, J. Introduction to Basic Cardiac Dysrhythmia 3rd Edition. MosbyJems. 2003.Bledsoe, B., Porter, R., Cherry, R. Paramedic Care Principles & Practices Third Edition. Brady. 2009. Page, B. 12 Lead ECG for Acute and Critical Care Providers. Brady. 2005.Previous CMC Cardiac CEsRegion X SOP March 2007; amended January 1, 2008Various webpagesFor pictures, rhythms, and graphsWalraven, G. Basic Arrhythmia 7th Edition. Brady. 2011.www.MikeCowley.co.uk/leads.htm

Time is measured horizontally. Amplitude, or voltage, is evaluated by number of boxes cumulatively above/below the baseline. Amplitude, or voltage, is the strength of the current.Depolarization does not guarantee that a contraction occurred. Contractions must be evaluated by feeling for a pulse and measuring the blood pressure. Depolarization is an electrical response and contractions are a mechanical response.SA node is hearts dominant pacemaker site with an inherent rate of 60-100 beats per minute. As you move down the conduction system, the pacemaker site becomes slower and is less reliable.Inherent rates:SA node 60-100AV node 40-60Ventricles 20-40Delta wave is the slurring at the uptake of the QRS complex.TdP Torsades de Pointes. QRS is wide, > 0.12 seconds, and bizarre with a rate often over 150 beats per minute.Long QT interval is measured as more than one half the R to R interval for that complex and the R wave following that complex. OPQRST O onset (what were you doing at the time of onset?)P provocation/palliation (what makes it worse; what makes it better?)Q quality in the patients own wordsR radiation to any where?S severity measured on the 0-10 scaleT what time did the symptoms start?Arm and leg leads may be placed on extremities or on the torso simulating right arm, left arm, right leg, and left leg.CX is the circumflex artery. Starts from the left descending artery and wraps around to the back of the heart.Think 2 main limb leads reverse themselves for reciprocal changes: - II, III, aVF reciprocal for I and aVL - I and aVL reciprocal for II, III, aVF Sensitivity measurement looks for >1mm elevation in contiguous leads. Specificity measures fro >2mm ST elevation in the chest (V) leads. Sensitivity will identify disease. Specificity may pick up less false-positives. In EMS, it is best to practice sensitivity than specificity in order to capture a broader number of potential patients and treat them as if they are having an acute MI rather than under treat and possibly miss an acute episode.Blood does not back up in the lungs; the right ventricle is not pumping well so there is no pulmonary edema from a right ventricular infarct (RVI).Pain level most likely will not be zero until the block has been removed and circulation has been restored.*Note presence of Delta Wave slurring of beginning of the QRS complex*Patients symptoms will be dependent on the heart rate the slower the heart rate the more symptomatic the patient will be.Focus on the P wave irregularity, not necessarily the name of the rhythm. Can be referred to as a rapid wandering pacemaker.*Reciprocal changes in I, aVL, V1, V2.Reciprocal changes are ST depression seen in I and aVR if the ST elevation is in II, III, aVF.Note reciprocal changes of ST depression in II, III, and aVF.Serious infarct with high mortality rate (widow maker) due to occlusion high in the left anterior descending (LAD) coronary artery.It is not appropriate to wait until moving the patient to the ambulance before obtaining the 12 lead EKG. You may not be able to transmit the 12 lead until you have the patient and monitor back in the ambulance but you can obtain one and review where you first made contact with the patient.