Heart Anatomy & ECG KAAP 310

The Electrocardiogram (ECG) As we discussed last week, the electrical activity of the heart is determined by pacemakers (SA, AV node) By placing sensitive electrodes on certain parts of the body, we can recognize and record the “echoes” of the heart depolarizing and repolarizing Heart rate, Axis deviation (heart position), cardiac arrthymias and mechanical activity of heart can all be seen on a standard ECG.

A normal ECG reading QRS Complex: R & L ventriular depolarization, Atrial repolarization masked by QRS complex T Wave: Repolarization of right and left ventricles P Wave: Depolarization of the right and left atria (atrial depolarization)

Reading & Interpreting an ECG Segments: Periods of no recorded activity in the heart Isoelectric Line: Point of departure of the depolarizing and repolarizing actions of the heart. Interval: Period of electrical activity within and between heartbeats

ECG Leads Particular arrangement of the electrodes with respect to one another is called a lead. We will be using a 3-lead model A positive, negative and ground electrode will be placed on the subject + on left ankle - on right wrist Ground on right ankle

ECG Notes QRS complex generally dominant in any ECG recording Affected by many factors: Body mass, fat mass, height, cardiovascular health (large LV mass will change the look of the complex)

Large & Small Block Calculations Can go over ecg graph here, perhaps talk about small block r-r interval to determine heart rate

BioPac Lab Four conditions will be recorded: Supine, Seated, Breathing deeply, and After exercise. Minimize EMG artifact and baseline drift: Subject’s arms and legs must be relaxed. Subject must remain still and should not talk during any recordings. Make sure electrodes do not peel up and that the leads do not pull on the electrodes. Cable artifact is created when cables are unnecessarily handled/moved Make sure baseline is stable before beginning procedure

BioPac Lab First condition: Supine, eyes closed, relaxed Second condition: Stand up quickly, settle back down into seated position Third condition: Five (5) deep inhales/exhales with recorder counting Fourth condition: Exercise – 15 pushups or 15 jumping jacks. Mind the cables – may unclip if necessary…don’t forget to re-attach! Optional active learning portion not required Call your TA when you have collected all data

Data Review After your data file has been transferred to your laptop, open it with your BioPac analysis software and begin analyzing your data Data & questions can be completed on your computer and emailed to your TA (due next week)

Heart Models While your group is waiting to work with the BioPac software please use this time to begin reviewing the heart models These same models will be used for your first long quiz Feel free to use online resources and this presentation Models will be available next week during our dissection lab as well

Cardiac Anatomy

Interatrial Septum Interventricular Septum

Brachiocephalic trunk Left subclavian artery Superior vena cava Left common carotid artery Brachiocephalic trunk Left subclavian artery Superior vena cava Aortic arch Ligamentum arteriosum Right pulmonary artery Left pulmonary artery Ascending aorta Left pulmonary veins Pulmonary trunk Right pulmonary veins Auricle of left atrium Circumflex artery Right atrium Left coronary artery (in coronary sulcus) Right coronary artery (in coronary sulcus) Anterior cardiac vein Left ventricle Right ventricle Great cardiac vein Right marginal artery Anterior interventricular artery (in anterior interventricular sulcus) Small cardiac vein Inferior vena cava Apex (b) Anterior view Figure 18.4b

Right pulmonary artery Aorta Superior vena cava Left pulmonary artery Right pulmonary artery Right pulmonary veins Left pulmonary veins Auricle of left atrium Right atrium Left atrium Inferior vena cava Great cardiac vein Coronary sinus Right coronary artery (in coronary sulcus) Posterior vein of left ventricle Posterior interventricular artery (in posterior interventricular sulcus) Left ventricle Apex Middle cardiac vein Right ventricle (d) Posterior surface view Figure 18.4d

(a) The major coronary arteries Aorta Pulmonary trunk Superior vena cava Left atrium Anastomosis (junction of vessels) Left coronary artery Right atrium Circumflex artery Right coronary artery Left ventricle Right ventricle Anterior interventricular artery Right marginal artery Posterior interventricular artery (a) The major coronary arteries Figure 18.7a

(b) The major cardiac veins Superior vena cava Great cardiac vein Anterior cardiac veins Coronary sinus Small cardiac vein Middle cardiac vein (b) The major cardiac veins Figure 18.7b

Aorta Left pulmonary artery Superior vena cava Right pulmonary artery Left atrium Left pulmonary veins Pulmonary trunk Right atrium Mitral (bicuspid) valve Right pulmonary veins Fossa ovalis Aortic valve Pectinate muscles Pulmonary valve Tricuspid valve Left ventricle Right ventricle Papillary muscle Chordae tendineae Interventricular septum Trabeculae carneae Epicardium Inferior vena cava Myocardium Endocardium (e) Frontal section Figure 18.4e

(right atrioventricular) valve Area of cutaway Myocardium Pulmonary valve Aortic valve Tricuspid (right atrioventricular) valve Area of cutaway Mitral valve Tricuspid valve Mitral (left atrioventricular) valve Myocardium Tricuspid (right atrioventricular) valve Aortic valve Mitral (left atrioventricular) valve Pulmonary valve Aortic valve Pulmonary valve Aortic valve Pulmonary valve Area of cutaway (b) Fibrous skeleton Mitral valve Tricuspid valve (a) Anterior Figure 18.8a