CVS Revision PDF

Physiology revision Sem 4 cvs Arterial Pulse  Pulse Pressure It is a pressure wave, which travels down the arteries The arterial pulse can be felt in the superficial arteries Sites of Palpation of Pulse Pressure 1. Common carotid...

Physiology revision Sem 4 cvs Arterial Pulse  Pulse Pressure It is a pressure wave, which travels down the arteries The arterial pulse can be felt in the superficial arteries Sites of Palpation of Pulse Pressure 1. Common carotid artery 2. Radial artery 3. Femoral artery 4. Tibial artery 5. Dorsalis pedis artery Sites of Palpation of Pulse Pressure How to palpate radial pulse Proximal finger Middle finger Distal finger 1. Palpate the pulse by placing the middle three fingers on the palmer surface of the forearm just above the wrist and medial to the tendon of brachioradialis muscle. 2. By the proximal finger, exert a slight pressure over the radial artery producing turbulent blood flow. 3. Exert a high pressure by the distal finger over the radial artery to prevent any back arterial pulsation. ❖ The radial pulse is felt by the middle finger. How to comment on radial pulse 1. Rate: Count the number of beats during one minute. 2. Rhythm: Note whether it is regular or irregular. Heart sounds  Methods of Detection of Heart Sounds a)Stethoscope: 2 sounds are only audible by stethoscope b) Phonocardiograph: records for 4 sounds → phonocardiogram  Medical Stethoscope It consists of 3 parts: a. Chest piece → consists of 2 parts ❖Cone or bell → for low intensity sounds ❖Diaphragm →for high intensity sounds b. Ear pieces. c. Rubber tube (50-75 cm).  Medical Stethoscope Uses of stethoscope: 1. Auscultation of heart sounds. 2. Auscultation of breath sounds 3. Auscultation of intestinal sounds 4. Measurement of ABP. Auscultatory Areas  First Heart Sound (S1) Duration 0.15 second Relation to cardiac At the beginning of ventricular systole (ICP and MEP) cycle Causes: Sudden closure of AV valves (tricuspid and mitral) Characters Soft and low pitched (25-40 Hz) sound. Heard as the word Lub by the stethoscope. Auscultatory sites a- Mitral area (M): left 5th intercostal space at MCL b-Tricuspid area (T): left 4th intercostal space near sternum  Second Heart Sound (S2) Duration 0.1 second Relation to At the beginning of ventricular diastole (IRP) cardiac cycle Causes: Sudden closure of semilunar valves (aortic and pulmonary valves) Characters Sharp and high pitched (50 Hz) sound. Heard as the word dub by the stethoscope. Auscultatory a- Aortic area (A): 2nd right intercostal space near sternum sites b- Pulmonary area (P): 2nd left intercostal space near sternum  Third Heart Sound (S3) Duration 0.05 second Relation to Mid part of the ventricular diastole (RFP) cardiac cycle Causes: It is due to vibrations of the relaxed ventricular wall and of the cusps of AV valves Characters It is a low pitched sound that can sometimes be heard only in children. Auscultatory It is best heard at the mitral area, while the person sites is in recumbent position and leaning to the left side  Fourth Heart Sound (S4) Duration 0.03 second. Relation to Atrial systole→ presystolic HS cardiac cycle Causes: It is due to vibration of the cusps of the AV valves due to rush of blood from the atria to the ventricles Characters It is a faint low pitched sound that is normally inaudible both in children and adult. Auscultatory If heard abnormally it is heard at the mitral area. sites Heart Sounds Abnormalities  Heart Sounds Abnormalities HS Abnormalities Splitting of HS Triple Rhythm Murmur  Splitting of Heart Sounds Def., The HS is heard as 2 sounds separated by a very short interval. Causes: It is due to asynchronous closure of valves on both sides of the heart.  Triple or gallop Rhythm Def., It is an abnormal condition in which three heart sound are heard resembling the sound of a galloping horse. Causes and types: It occurs in heart failure, it is either; 1. Protodiastolic gallop→ third heart sound is the 3rd sound. 2. Presystolic gallop→ 4th heart sound is the 3rd sound.  Murmurs Def., They are abnormal noisy sounds heard over the heart other than the heart sounds. Systolic murmurs Diastolic murmurs Continuous murmurs Time Occur during ventricular Occur during cardiac Occur during systolic systole i.e. in the interval diastole i.e. after the 2nd and diastolic periods between the 1st and 2nd heart heart sound (machinery murmur) sounds. Causes Stenosis of aortic or stenosis of mitral or Patent ductus arteriosus pulmonary valve. tricuspid valve. Regurge of mitral or tricuspid Regurge of aortic or valve. pulmonary valve. Arterial Blood Pressure (ABP)  Arterial blood pressure (ABP) Def., ABP; Is the lateral force exerted by the moving column of blood on the lateral walls of arteries. ABP is expressed as systolic over diastolic.  Arterial blood pressure (ABP) Systolic BP: is the maximum pressure caused by the ejected blood during peak of ventricular systole normally 90-140 mm Hg. Diastolic BP: is the lowest pressure at the end of ventricular diastole normally 60-90 mm Hg  Pulse pressure Pulse pressure : difference between systolic and diastolic pressure Pulse pressure: systolic pressure – diastolic pressure Normal range in adult is 30 to 50 mm/Hg  vital signs ABP is one of the vital signs. Vital sign; Blood pressure Heart rate Respiratory rate Oxygen saturation Temperature : Factors affecting ABP Sex … M > F …due to hormones/ equal at menopause. Age … Elderly > children …due to atherosclerosis. Emotions … due to secretion of adrenaline & noradrenaline. Exercise … due to  venous return. Hormones … (e.g. Adrenaline, noradrenaline, thyroid H). Gravity …  Lower limbs > upper limbs. Race … Orientals < Westerns … ? dietry factors, or weather. Sleep …  due to  venous return.  Types of sphygmomanometer Mercury Aneroid  Types of sphygmomanometer Digital Hybrid Mercury sphygomanometer  Components of sphygmomanometer Rubber bag in apiece of clothes Connected to 2 rubber tubes One attached to valved pump to inflate &deflate the bag The other connected to mercury scale with on/off valve  Technique The subject: recumbent position or comfortably seated, no recent exercise ,meals, coffee, smoking or apprehension. The arm: should be bared, slightly fixed, abducted, relaxed & quiet surrounding. The manometer: center of completely deflated rubber bag placed on brachial artery with clear cubital fossa 2.5 cm above elbow bend, mercury at zero point , appropriate size. The manometer: seen by observer not by subject, put on stable table on level of the heart  How To Measure ABP: Palpation Method Gives a rough idea about value of systolic BP: Apply the cuff to upper arm. Your middle 3 fingers of one hand feeling radial pulse. Using the other hand, inflate the cuff till pulse disappears. Slowly deflate the with your eyes at the manometer; the value at which u feel the pulse again is the Systolic BP  How To Measure ABP : Auscultatory Method With the cuff still around the upper arm (NOTICE THAT CUBITAL FOSSA MUST BE CLEAR) Place the stethoscope on anatomical site of brachial artery (medial side of antecubital fossa, medial to bicepes tendon u can feel its pulse) Raise the pressure in the manometer by about 10-20 mm Hg above the value that u measured by palpation method before Start to deflate very slowly (by 2mm Hg) until u hear sound; Korotkov’s sounds  Auscultatory Method The 1st appearance of sounds indicates systolic BP. The intensity of sound increases (blowing) as the pressure in cuff is decreased (Turbulent flow). Sound is muffled gradually then disappears indicating Diastolic BP.  PRACTICAL NOTES The doctor; must be on the RT side of the subject. The doctor measure ABP on the RT arm (RT 0.2 second in: i- vagal stimulation. ii- 1st degree heart block. iii- atrial hypertrophy. B) Shortened P-R < 0.12 second in: i- symp. stimulation. ii- A-V nodal Rhythm. C) Absent in: i- complete heart block. ii- Some cases of A-V nodal rhythm.  Q-T interval - is the interval from beginning of Q to the end of T. - normally = 0.4 sec. - Significance: it represents the time needed for ventricular depolarization & repolarization. Q-T interval  Q-T interval Abnormalities of Q-T interval: A) Prolonged in: - hypocalcaemia. - Ischemia B) Shortened in: - hypercalcaemia - digitalis toxicity  S - T segment - is measure from the end of S wave to the beginning of T- wave. - the normal duration is 0.12 second. - normally , during this segment the ventricular ms. is completely depolarized (isoelectric). S - T segment  S - T segment Abnormalities of S-T segment: 1- Elevated S-T segment, in case of: i- recent myocardial infarction ii- pericarditis 2- Depressed S-T segment, in case of: i- ischemia ii- ventricular extrasystole. ST segment elevation  Cardiac Axis The QRS axis represents the net overall direction of the heart’s electrical activity. the normal QRS axis is defined as ranging from -30° to +90°. -30° to -90° is referred to as a left axis deviation (LAD) +90° to +180° is referred to as a right axis deviation (RAD) How to know if cardiac axis is normal or deviated? Look at R wave in Lead 1 & aVF both I and aVF +ve = normal axis lead I -ve & aVF +ve = right axis deviation (e.g.RV hypertrophy) lead I +ve & aVF -ve – lead II +ve = normal axis – lead II -ve = left axis deviation (e.g. Lt V hypertrophy)  Axis Quiz Right axis deviation. Positive QRS in lead aVF, but negative QRS in lead I.