ソース: Suneel Dhand、MD、医師、内科、ベス イスラエス ディーコネス メディカル センターに参加
心臓の音と正常と異常な心臓の音を区別する能力を聴く聴診器の使用中の能力は、任意の医師の必要不可欠なスキルです。胸に聴診器の正しい配置を閉じる心臓の弁の音に対応しています。心臓が 2 つの主要な音: S1 と S2 です。帽として最初の心臓音 (S1) に発生し、血液が心室に入る後に三尖弁 (房室弁) を閉じる。これは収縮期の開始を表します。第 2 心音 (S2) は、大動脈弁と肺動脈弁 (半月弁) が血液が心室収縮期の終わりに全身および肺循環システムを入力するを去った後を閉じるときに発生します。伝統的に、音が「lub-ダブ。」として知られています。
聴診器のチェスト ピースのダイヤフラムおよび鐘の部分を使って心臓の聴診を行います。横隔膜は、最もよく使用して僧帽弁閉鎖不全症、大動脈弁狭窄の雑音の高周波音 (S1 および S2) などに最適です。横隔膜は胸部の壁にしっかりと押す必要があります。最高の鐘 (S3 ・ S4 などの低周波音と僧帽弁狭窄症のつぶやきを送信します。ベルは、光の圧力を適用しなければなりません。
Auscultation of the heart remains one of the fundamental skills for any clinician to master, and it provides vital diagnostic clues to many cardiac abnormalities. Learning the correct technique for auscultation is essential in order to distinguish the normal from the pathological. All cardiac areas must be auscultated in a structured and methodical fashion. The physical findings should be interpreted with respect to the cardiac cycle, and the intensity, duration, pitch, and timing of each sound should be noted. It is essential to memorize the anatomical landmarks where the stethoscope should be placed on the patient's chest, and always examine the patient in a quiet environment. It is important to listen for at least 5 sec, while the patient is breathing normally, to avoid one of the common mistakes made during the physical exam – not allowing adequate time to listen to the heart sounds. Physicians must be familiar with their stethoscopes and engage both the diaphragm and the bell during the heart auscultation.
Proficiency in the use of a stethoscope to listen to heart sounds and the ability to differentiate between normal and abnormal heart sounds are essential skills for any physician.
The heart has two main sounds, S1 and S2. The first sound – S1- occurs as the mitral and tricuspid valves close, after blood enters the ventricles. This represents the start of a systole. The second heart sound – S2 – occurs when the aortic and pulmonary valves close, after blood has left the ventricles to enter the systemic and pulmonary circulation systems at the end of a systole. Together, they sound as “lub-dub”… “lub-dub”.
In this video, we’ll first review the surface landmarks for auscultation, and then we’ll go through the essential steps for this exam. The discussion related to the abnormal heart sounds such as murmurs and gallops will be covered in a separate video of this collection.
Let’s begin by reviewing the surface landmarks for auscultation. As discussed,
The aortic area corresponding to the aortic valve is along right sternal edge of the 2nd intercostal space, abbreviated as the 2nd ICS. Similarly, at the left sternal edge of the same ICS is the pulmonic area associated with the pulmonic valve. Travelling down the left sternal edge, in the 4th or 5th ICS is the tricuspid area corresponding to the tricuspid valve. And in the 5th ICS along the mid-clavicular line is the mitral area linked to the mitral valve.
Now that you’re familiar with the landmarks, let’s review the sequence of steps for this exam. Before starting the procedure wash your hands thoroughly and make sure that the stethoscope has been cleaned with a disinfectant wipe.
First, familiarize yourself with the stethoscope chest piece. The auscultation of the heart is performed using both – the diaphragm and the bell. The diaphragm is best for high frequency sounds, such as S1 and S2. The bell best transmits low frequency sounds, such as S3 and S4.
Begin by ensuring that the area to be examined is exposed, and request the patient to lie down at a 30-45° degree angle on the exam table. Before placing the stethoscope, a good rule of thumb is to locate the 2nd ICS by palpating for the Angle of Louis, which is at the level of the 2nd ICS. Next, place the diaphragm at the right sternal edge of this ICS, which is the aortic area. Listen at each auscultation spot for at least 5 seconds to ensure that you’re not missing any subtle sounds. In addition, throughout the exam ask the patient to breathe in and out, because in presence of an abnormal sound, the timing in the respiratory cycle can provide a vital diagnostic clue. While auscultating the aortic area, listen for S2, which represents the aortic valve closing. Next, move to the pulmonic area, which is on the left sternal edge of the 2nd ICS. Here, again you can clearly distinguish the second heart sound, which represents the pulmonic valve closure. Subsequently, using the diaphragm, auscultate the tricuspid area at the 4th or 5th ICS on the left sternal edge. Here, listen for the first heart sound due to the tricuspid valve closing. Lastly, place the diaphragm in the mitral area and listen for S1, which represents the mitral valve closure.
In addition to the four valve-associated landmarks, auscultation of the lungs and major arteries can provide essential information regarding the cardiovascular functioning. Using the diaphragm, auscultate at the base of the lungs to listen for any crepitations or crackles, which indicate pulmonary edema, a sign of heart failure. Next, with the bell, auscultate the carotid arteries. Frequently, a murmur that is present from the aortic valve may be heard in this area. Also, auscultate here for a bruit, which is a swishing sound produced by turbulent blood flow, a sign of carotid artery stenosis. Finally, to assess for peripheral vascular disease, auscultate for abdominal bruits at the aorta area, renal arteries, and femoral arteries.
You’ve just watched JoVE’s presentation on cardiac auscultation. The video reviewed important auscultation landmarks and illustrated how to perform the steps of this exam in a structured fashion.
Auscultation of the heart remains one of the fundamental skills for any clinician to master, and it provides vital diagnostic clues to many cardiac abnormalities. Therefore, learning the correct technique for auscultation is essential in order to be able to distinguish normal from pathological. As always, thanks for watching!
