Auscultation of the chest drum

1. Gastroepato
2. Cardiology
3. The chest drum
4. Practical anatomy of
   the heart and large vessels
5.  Cardiac semeiotics
6. Chest pain
7. Chest pain of myocardial origin

notes by dr Claudio Italiano

All you wanted to know about the heart, always with the apology for cardiologists, we have brought back to you on this simple web page, addressing to our devoted audience of gastroepaters, who are not always doctors or professionals. So, first of all, you should know that the heart is made up of 4 chambers, that is, four cavities, two upper and two lower, respectively the atria and ventricles, of which the right ventricle is smaller than the left, due to the fact that it pushes the blood in the "small circulation", that is, in the pulmonary circulation and, therefore, it pumps large volumes of blood but at low pressure. Then the pressure that develops will be at most 20 mmHg, while the left ventricle takes care of pushing the blood in the "great circulation" or also called "systemic circulation", ie pushes the blood to all organs of the body, since they require oxygen contained in it and nutrients (oxidizing and combustible).
The pressures with which the left ventricle works are around 120-130 mmHg, so its wall is developed 3-4 times more than the right ventricle, but it can not be hypertrophic, because if it were, it would soon with decompensation. The reason why you find it in the related pages to which the links refer. Now, in order for the blood to be pumped, the respective atriums are filled with blood first, and then the blood passes to the respective ventricles (right atrium with right ventricle and left atrium with left ventricle).

Between these chambers, that is between the respective atria and ventricles, there are some valves as you can see in the picture, the mitral valve on the left and the tricuspid on the right. Generally the valves have a good seal and allow flow to flow in one direction. But for various diseases including endocarditis or also because the heart goes into pump failure and gets enlarged, expanding, the valves then no longer hold and, so to speak, "vent". This venting is perceived in the sensitive ear of the cardiologist as a breath noise, but also as a "click" noise, a sign that the valve is free or deformed (always with apologies for cardiologists, who will read this page!) .

Now, you still have to know that there are two other important valves, the aortic (see aortic valvulopathy) and the pulmonary, which close the door to the flow once the blood has been pushed into the systemic and pulmonary circuit respectively. That being the case, it would seem that everything is within the limits of the norm, but, unfortunately, in the reality of the clinic, it is not so, because every day the doctor runs into sick hearts or due to hypertension (see Arterial hypertension complications in the patient with arterial hypertension The arterial hypertension: the pharmacological cure) that makes them become hypertrophic in their left ventricles, or because of valvulopathies or because of ischemic heart disease, a very frequent complication in the patient with diabetes, for example.

Let's see in particular what to hear in the patient's chest

Listening to the heart is one of the most simple but at the same time one of the most complex methods of semiotics. To begin, we must know that the heartbeat of our chest drum (as a beautiful song by the Pooh used to say!) Is rhythmic, that is, the heart is directed by a great orchestra master who is his natural pacemaker, that is, the knot of the breast, which is endowed with a great characteristic: it manages to automatically generate the contraction of the heart, before the atria and then spreads the signal to the ventricles to make them contract synchronously and adequately. So the doctor must understand if the rhythm is adequate, that is, regular, if the contraction is valid, if there are noises of "breath", when the valves are worn out and do not keep the blood in the chambers or if they are stenotic, ie the flow the blood is turbulent because it passes into a narrow slot. But first of all he must "make his ear", that is, recognize the right sounds and then be able to discern the pathological ones.

 Listen. >>normal heart tones
Patient trouble, for example, with aortic stenosis, where the valve surface is reduced to less than 0.8 cm square! They will have to contact the cardiac surgeon for what to do. The vibrations that originate from the heart are in the order between 30 and 500 Htz, that is of its bass, that are perceived supporting the bell of the phonendoscope on the breast, in certain points. The acoustic phenomena of the heart essentially have a valve origin. My professor spoke of "mucus-aortic walk", and spoke of anatomical foci and auscultation areas:

Anatomical areas

Projection of the mitral valve, at the sternal insertion of the IV rib on the left
Projection of the tricuspid valve at the height of the V right intercostal space, in the sternal back.
Area of the aorta, mid-sternal at the third intercostal space;
Pulmonary area, sternal margino, at the height of the third left rib cartilage.
Auscultation areas are:
• Tip of the heart to the left V intercostal space within the michral valve hemiclavicular line
• Left and right sternal border at the IV space for the tricuspid
• The right intercostal space on the sternal margins, for the aorta
• The left intercostal space on the sternal margins for the lung

But what should we listen to?

Certainly the drum of the chest, that is the beats and the heart that beats in two tones. The first corresponds to the beginning of the systole, that is, to the moment in which the heart, closed the two mitral and tricuspidal valves, contracts. These tones are produced, therefore, by the muscular walls and, mainly, by the valves when they close, or by the blood flow that passes through them. The second tone, higher than the first and shorter ones, is given by the initiation of the diastole, that is of the ventricular filling, and originates from the closing of the pulmonary and aortic semilunar valves. By convention it is said that the two tones correspond to the syllables "tum" and "ta" and so on. When the valves close as a result of the pressure rise in the downstream chambers, they produce a short vibration that resembles the sound of a sail filled by the wind. This vibration is transmitted to the walls of the chest, where it can be perceived with the hand or heard by the doctor through the phonendoscope or recorded by a phono cardiograph and by the echocardiograph.
 

Summing up..
The audible tones of the human ear in the healthy individual are two, called first and second.

The first tone is a vibration between 5 and 100Hz, caused by the almost simultaneous closure of the tricuspid and mitral valves at the beginning of the systole. In the electrocardiogram it corresponds to the P-R wave complex. The first tone (S1) corresponds to the closure of the mitral and tricuspid valves. The "sound" is produced mainly by the left ventricular muscle and the mitral. It is composed of a mitral component (M1) and a subsequent (20-30 msec) tricuspidale (T1). It marks the beginning of the systole. You feel better at the tip or left ventricular area
• The second tone is 50-150Hz, generated by the closure of the pulmonary and aortic valves. In the ECG exam, it corresponds to the end of the T wave. The second tone (S2) corresponds to the closure of the aortic and pulmonary valves. The "sound" is produced by the vibrations of the closed valves and rapid deceleration of the flow. It is composed of an aortic component (A2) and a subsequent pulmonary component (P2). It marks the end of systole and the beginning of diastole. It feels better at the base or aortic and pulmonary areas
In both tones the two components can be auscultated separately, especially under certain conditions, both physiological and pathological. The splitting of the second tone is, for example, easier to observe in the young and during the breath. Two other tones, of low frequency, and therefore imperceptible to the human ear, are the third and fourth tones (called in pathological conditions respectively a ventricular gallop and atrial gallop).
The third tone appears about 200ms after the second, and is caused by the abrupt filling of the ventricle. It is typically audible in children and subjects with high range.
The fourth tone precedes the first by about 100ms, and is instead generated by the atrial systole

Murmurs and snap opening of the mitral valve.

Listen >>Murmur from aortic stenosis

Listen >> Gallop rhythm

Another thing to know is the murmurs and the snaps. The breaths constitute acoustic events that are located in the small pause, in the big pause or in both and are represented by vibrations between 60 and 600 htz, like the noise of the murmurs with half-closed lips.

They depend on:
- Increased flow through the valves, especially if restricted
- Anterograde ejection flow
- Retrograde flow, ie regurgitation through the insufficient valve (frequent occurrence), means that the valve "does not hold" and the blood goes back, increasing the work of the heart that has to push the passing blood + the one that flows back (caput mortuum).
- Flow through cardiac short circuits or shunts

The murmurs should be distinguished in 6 degrees, depending on the classification of Levine in weak breath o1 / 6, weak breath 2/6, moderate breath 3/6, strong breath 4/6, very strong breath 5/6, very strong breath 6 / 6.

The opening pops are sounds that are generated by pathological valves, for example in the mitral stenosis, probably due to incomplete opening of the valve, which is stiffened and thickened, as if of dry and rapid noise.

opening snap

Cardiology