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Thursday, September 23, 2010

6.15 Paul Dudley White Method to Study Heart


Physician's Notebooks 6 -Homepage  http://physiciansnotebook.blogspot.com
15. Physical Signs of Heart Function (Update 21 Jan. 2017)
Paul Dudley White (1886-1973) was a great cardiologist and he wrote a book Heart Disease, which is a good read. I give here his way to do a heart examination. And I add from Dr White's student, Dr. J. Willis Hurst's The Heart, 13th ed, 2011 and from my nearly 60-year experience. Read it in segments as seminars using self and others as doers and subjects of the examinations to learn it usefully.
The over-printed lines on the front chest photo show a normal heart outline (The outlines and rib locations have all been double checked by a normal's chest x-ray) and also include the clavicles (as dotted, collarbones). The “MCL” from the left clavicle as dotted line is “mid clavicle line.” The 1, 2, 3, 4, 5 are the left ribs. The outline of the heart is by chest percussion and confirmed by x-ray.
  A normal heart apex (“APEX”) should not extend further out than the MCL. On the subject's left, the heart outline's larger, lower curve is the edge of the heart's left ventricle, the next smaller curve, just above, is the left lateral edge of the descending aorta just where the aorta has completed its arch. The topmost border of right side of the heart is from large entry veins and the normal outline of the right atrium and the lower curve outline is the right ventricle. Also note, extending from each side of the lowest part of the heart, the convex upwardly curved lowest ribs margin which outlines the upper border of the diaphragm muscle.
Inspection is done on the patient's bare chest with the patient sitting, relaxed. The ideal bare chest for the examination should be slim, flat and not hairy, and no full stomach. Inspect the front chest for the heart action. Use the bare chest photo above to know where to look. First try to see the apex beat just inside or on the left MCL at nipple line. If you do not see it, that is normal. An out-thrust outside of the MCL is a sign of an enlarged heart. Enlarged hearts give large, diffuse out-thrusts at and beyond apex.
Palpation
Do Palpation for finding the apex impulse on yourself or other person. Place palm of right hand over your left breast, with middle finger extending out just past the left nipple and firmly pressing the balls of your 2nd, 3rd and 4th fingers into the soft tissue of the breast (a full breasted woman should lift her own breast out of an examiner's way) down to feeling the ribs and rib inter-spaces. Your finger should be extended parallel to the rib inter space and each finger should fit into an inter space. Having the examined person lean forward and exhale all breath and not breathing for an interval helps bring out the apex impulse. In a quiet resting condition, it may be barely felt. At rest, a strong, heaving apex impulse or one outside the MCL means an enlarged heart. Feeling an impulse that has a different quality from the slight out-thrust is abnormal. Most definitely abnormal is a thrill – a vibratory feeling with each heartbeat, which would be equivalent of a rough humming.
Percussion
of chest wall to determine heart enlargement and normality of shape uses your right middle finger pressed against the examined person's chest, and your left middle fingertip is used like a percussion hammer. Good position for self percussion is sitting.
   Lay your right middle finger in the ribs' inter-space at or just below the left nipple, with your mid knuckle (2nd finger joint) on or below the nipple. The finger should be pressed firmly but not tensely against the inter space. The percussion tap should be given by your left middle fingertip with your left elbow bent so that your left forearm is parallel with your right middle finger. The tap movement should be from your wrist and not your elbow or shoulder. It should be a moderate tap with your tapping left fingertip striking the fingernail. The sound, with a normal size heart and tapping outside MCL should be drum-like because you are tapping over aerated lung tissue. If a dull or a flat tap outside the MCL at nipple level, it means an enlarged heart. If you get a drum-like sound out to the nipple, then position your right middle finger so that its fingertip is more toward the middle of chest and then repeat your fingertip taps. Normally the drum-like sound of your tap should change to a dull tap between the left nipple and the breastbone (sternum) as you, the examiner, move the tapping towards the mid line of an examined person's bare chest. The spot where the drum-sound tap changes to a dull tap is the left border of the examined heart at that level. In a slim person with a normal heart, it should be midway between the breastbone border and left nipple.
   On right side of the chest also at nipple level, a percussion should be drum-like to the right breastbone border. Finding fingertip tap dullness on the right side out from the breastbone at this level means an enlarged right heart.
  Repeat the percussion at the level of the 2nd and 3rd rib inter-spaces, on left and right breastbone borders. There, normally, the percussion note should be drum like. A wide area (wider than 1 cm, or 0.4 inch) of dullness at this level is abnormal and usually means an enlarged heart atrium (in young person) or aortic aneurysm (in old person).
Auscultation - Listening to Heart
The heart is best heard by listening (cf.Yogi Berra wisdom) to and felt by its vibrations. Your ears and fingers start that but it needs a stethoscope to get the best sounds. The best place to buy a stethoscope is medical supply store by a medical school. Before buying, be sure the earpieces are comfortable. Also that the stethoscope chest-piece has on one side a flat, circle diaphragm and on the other a plastic hollow-cone-shape sound-transmission hearing-piece that can be easily switched, one to the other. For best sound transmission, the stethoscope should have the listening end connected to the earpieces by a separate plastic or rubber tube for each piece of as short a length as convenient for you the user. The usual length on buying is 12 inches, or 30 cm, but I cut that length down by scissors so that my tube length is 6 in. or 15 cm. You need to lean close to the person you are examining but you hear the heart better. 
Stethoscope as described in text above, from Dr Paul Dudley White's Heart Disease in 1935. Note the separate chest pieces - the flat, circle diaphragm for high pitched sounds and the cone for low pitch. Today, they are flip-switchable. 
The human ear is most accurate at frequencies 1000 to 4000 Hertz (1-to 4-kHz; Hz, number of vibrations per second). Most heart sounds are between 30 and 1000 Hz and not easy to hear. The bell chest hearing-piece is best for low-frequency sounds like mitral valve rumble-murmurs; the flat diaphragm is best for high frequency sounds like hi-pitched aortic insufficiency. And the listening piece must be pressed firmly (but not tightly) against chest wall for best listening. Especially when trying to hear a heart murmur, one should use the bell piece with degrees of pressure against chest to bring out low-pitch murmur.
  The heart sound is best enhanced on yourself, sitting, leaning forward and to your left, by listening during an end-expiration, no-breathing phase, with the subject of the exam leaning forward in a downward direction so that the heart comes closest to chest wall.
  Locations on chest for listening are at heart apex and base (heart's base is 2nd to 3rd rib inter-space just to right and left of breastbone border) but at times an abnormal sound or murmur is better heard at other, nearby spot. The chest listening piece should be firmly but not tensely pressed on chest wall and held quietly as you listen to your own  or another heart.
Each heartbeat makes 2 easily detected heart sounds, heard over a normal heart and the timing of each sound in the heartbeat can be checked with your finger on a carotid heartbeat pulse in the subject's neck coming at same time as heart's 1st sound. The 1st sound is coincident with start of a heart contraction, or systole, and is heard loudest at the cardiac apex, where it may normally be twice as loud as a 2nd heart sound. The 2nd sound is coincident with the very early part of heart relaxation, or diastole. At heartbeat rate of 75 per minute, the first sound is 0.10 second duration and 2nd sound 0.08 second duration but that difference cannot be told apart by listening. The interval between sounds gets shorter as heartbeat rate gets faster. At slower heartbeat rates the 1st and 2nd sounds separate from each other because diastole (heart relaxation between beats), which determines timing of the 2nd sound, lengthens more than systole as heartbeat slows. At heartbeat of 75 per minute, the interval from end of 1st to start of 2nd sound is 0.25 second, and from end of 2nd to start of first, 0.37 second. Slower heart rates allow listener to more easily distinguish the two heart sounds and to detect 3rd or other abnormal heart sounds.
  The 1st heart sound is caused by the crunch of heart ventricle muscle as it contracts plus the slap-shut sound of the valves between atria and ventricles (tricuspid and mitral valves), which occurs just after the heart ventricles contraction. So three separate elements make up a 1st sound. The 2nd sound is the slap-shut of the aortic valve and, separately, the pulmonic valve of the ventricles after a contraction ends and a heart relaxation has begun. So the 2nd sound is made up of two elements. It is, normally, more discrete because the slap-shut valve sounds are sharp and higher pitched than the muscle crunch that makes up much of the 1st sound. It follows from the heart muscle's making up much of the 1st sound that abnormally weak first sounds are heard in heart muscle failure. The 2nd sound is abnormally faint when the aortic valve is fixed and rigid, as in an old-age, diseased heart. The heart sound heard by a stethoscope is sounded lub-dup. So as you listen to the beating heart you should imagine hearing “lub-dup … lub-dup … lub-dup … lub-dup …”.
Assuming your own heart is normal, listen to it much at first and get experienced in the lub-dup. There is a range in the quality of normal hearts. Since yours is the one you will be listening to at start, get used to its quality. Then when you hear an abnormal quality you will know the difference. The quality of heart sounds changes with age. In youth the sounds are sharper, shorter and louder; with aging they become slurred, fainter and prolonged. Sounds should be judged under controlled conditions: at normal rate at or less than 75 beats per minute, at same locations (apex & base) and same state of respiration (after complete exhalation and breath being held) and leaning forward position. 
The level of blood pressure (BP) may affect the sounds: high BP especially in youth causes a 2nd sound to be loud and sharp at the base over the aortic valve, in 2nd rib inter space at right border of breastbone. This is due to a more rapid, forceful slap-shut of aortic valve under force of increased back pressure in aorta during phase of heart relaxation. You may discover unrecognized high BP by the surprisingly louder 2nd sound at a heart's base, where, with normal BP the 1st and 2nd sounds should be of equal intensity. Oppositely, low BP (systolic below 110) should lead to a more faint 2nd sound. A rarer but related cause of increased 2nd sound at the base is pulmonary (lung) disease, due to high resistance (high Pulmonary Artery BP) in the pulmonary artery system and a strong slap-shut of pulmonic valve. This is heard best just to left of breastbone in 2nd rib inter-space. Each type of high BP (Systemic vs Pulmonary) gives split 2nd heart sound, loudest on left side of sternum for pulmonary hypertension and on right side for the usual systemic hypertension (See Split Sound  below)
  The first sound ups in intensity with any cause that increases heart rate and stroke volume such as coffee drink or other adrenergic drug, eg, cocaine. Also, exercise, intense emotion, fever, thyroid hormone over-activity or following a skipped beat ups in intensity. Best heard over apex.

Rhythm & Rate: Using your own body examination, get a sense of regularity of a heartbeat rate. A gross irregularity that continues beyond several beats is atrial fibrillation. It has no pattern to the irregularity. Another arrhythmia is a series of 3 to 5 regular beats followed by a missed beat; it is 2nd degree atrium-ventricle (A-V) heart block. An isolated irregular beat is a premature heart contraction (PC). A PC has the typical feature of a faint first beat in the regular sequence followed by long interval (the pause) and then a loud recovery beat. The explanation is that the first beat is the actual Premature Contraction coming early in the regular heartbeat cycle before the heart ventricles have a chance to fill with blood, so the muscle creak and the slap-shut valves sounds are fainter due to smaller than normal filling of ventricles. The following louder heartbeat sound is recovery of normal rhythm and delayed enough so the ventricle is over-filled with blood and thus contracts more strongly and gives louder sound.

Splitting of Heart Sounds: At rest, in a chair, a heartbeat's 1st and 2nd sounds are usually perceived at apex and base, each as a discrete sound; the first sound more loud at apex and 2nd sound more loud higher up, at base. Recall that the 1st sound is made up of the crunch of heart muscle contracting plus the slap-shut of valves between right & left atriums and ventricles and that the 2nd sound is the slap-shut of aortic and pulmonic valves just after the heart contraction ceases and the blood in aorta and pulmonary artery reverses and weighs down on the open aortic valve and the open pulmonic valve, slapping each one shut. Under normal resting condition, at end expiration, with breath held, the pulmonic valve slaps shut a small interval after the aortic valve but the interval is usually not long enough for the ear to sense; so the 2nd heart sound as listened to over the base of heart should normally be a single sound giving a heartbeat of 1st and 2nd sound that sounds like lub-dup. If, at end expiration, you hear, instead of the lub-dup, a sound like lub-duppit or lub-dupl, it means a split 2nd sound or some abnormality that will need echocardiogram. After deep inspiration (breathing in and holding) the 2nd sound is normally split so hearing a lub-duppit or lub-dupl right after breath-holding may be normal. Keep in mind, you should listen for split 2nd sound over base of heart. Respiratory motions, heart block, or disease of right or left heart valve or hypertension may produce splitting of 1st or 2nd sound after breath expiration (breathing out and holding) or inspiration. As in all auscultation, the 1st sound change is normally heard loudest over cardiac apex and the 2nd, over the base.
  With a first-sound split, instead of usual “lub-dup …”, you will hear something like “k-lub–dup”; but with second-sound split, it will be “lub–k-dup” or "lub-dupl "or“lub–duppit”. The 2nd part of the split is very close to the 1st part, so much so that its first part trips into 2nd part. Any longer interval is not reduplication but a 3rd heart sound, heard in other conditions and sometimes heard normally. If in doubt of splitting, a good test is to make it louder by a breathing maneuver. Normal heart 2nd sound splitting can be brought out by taking a deep breath and holding. Most splitting will be increased when a heart is slowed and will disappear with heart rate above 100 per minute. This will not happen with a 3rd heart sound, which should be well separated from the 2nd sound.

Gallop rhythm occurs at rate above 80 per minute; it is a 3rd heart sound that follows the 2nd sound but may come before it. The 3rd sound that makes gallop rhythm is usually something like “lub-dup-it” with a clear but close separation between the “lub-dup” and the “-it” in contrast to the closer connection of the lub-duppit sound in splitting. On rare occasion the gallop may come just before 1st sound in which case one hears “k-lub-dup …” or just after 1st sound, like “lub-a-dup.” The simulation of a horse’s gallop only occurs at rapid heart rate, 100 per minute or more. At slower heart rate it simply resembles 3 sounds without gallop quality. It is a serious sign of heart failure and when found allows one to predict death within a week so the subject is obviously seriously ill with shortness of breath or other signs.
   Tic-tac rhythm is a variation seen in severe heart failure in adults but is normal in a baby. It is heard best at cardiac apex and is due to weakening of first heart sound so that it equals the 2nd heart sound in intensity. That along with a rapid (>100 per minute) gives the sequential heart sounds the quality of ticking clock.

Heart Murmur is a rough or smooth vibratory sound separate from the discrete heart sounds although sometimes attached to their end or beginning. A murmur is either systolic, between 1st and 2nd sounds, or diastolic; starting, attached to, or right after 2nd sound or just before 1st sound. Some murmurs are continuous during the cycle, e.g., the machine murmur.
All murmurs are potentially serious and should be confirmed by cardiologist and then have echocardiogram to make anatomic diagnosis.  For an entertaining, fictional account of Paul Dudley White teaching students about heart murmurs, click 15.20 Paul Dudley White Appears on Rounds
 End of Chapter. To read next now, click 6.16 Heart Palpitation/Atrial Fibrillation

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