(1)
Hôpital Ambroise Paré Service de Réanimation Médicale, Boulogne (Paris-West University), France
The heart, this organ that prevents us to examine the lung…. Ph. Biderman (December 26, 2007)
We use the best of our 1992 Edition, Chap. 20 (the heart), born from the privilege of having been working in echocardiography in a pioneering institution [1], a typical spirit of intensive care, a discipline aiming at reaching its autonomy.
Even if they have the feeling to master the heart, readers would find interest in understanding the spirit of this chapter. The heart is a perfect example for holistic ultrasound. Simple signs, a simple technique and, mostly, its association with LUCI define a new field, fully distinct from traditional echocardiography (even the one devoted to the critically ill). The consideration of the BLUE-protocol and the FALLS-protocol will allow to position our simple emergency cardiac sonography between the traditional basic and expert echocardiography, aiming at making this traditional separation less necessary. Without lung ultrasound, the simple emergency cardiac sonography as defined would be insufficient. Therefore, this chapter will be fully understood only if integrated in the following chapters.
Obviously, prestigious works on expert echocardiography Doppler are numerous. They come from cardiologic fields [2], pioneering intensive care fields [1], many honorable sources [3], recent trends [4, 5], and so many sources that we can cite just a few, humbly apologizing for our lack of space [6–11]. This chapter will be poor in references, many hemodynamic references being inserted in Chap. 30 on the FALLS-protocol.
We use the simple emergency cardiac sonography since 1985/1989 and wrote the devoted chapter in 1992 (with no need for acronym; it was not a fashion in 1992, nor necessary). The basic echocardiography was popularized under several names, some rather elegant (the dynamic RACE of McLean, the FEER [12], FATE [13], etc., all now obsolete in the name of the recent FOCUS) [14]. This shows that, beyond the war of acronyms, the community took interest in this concept.
For taking the best of our approach, experts must understand that we deal with the very first minutes of management, when critical actions have to be done.
The term “sonography” on the title was chosen on purpose: for most, “Echo” means traditional Doppler echocardiography, while “ultrasound” (please note the lowercase) means traditional abdominal examination by a radiologist. Cardiology and radiology are two different worlds. Critical care is a completely distinct world, with its own logic.
The main protocols of LUCI (BLUE-protocol, FALLS-protocol, and SESAME-protocol) are fully cardiac centered. This is obvious for the FALLS-protocol, which begins by the heart, and the SESAME-protocol by essence (cardiac arrest). The BLUE-protocol aims at helping precisely when cardiac windows are lacking, another mark of interest. We just consider the heart as a vital organ like another, and this respect must be shared with other vital organs.
Our concept evolves as far as our main articles were published. We aim at providing a textbook increasingly complementary to the echocardiography textbooks. Consequently, from edition to edition (1992, 2002, 2005, 2010, etc.), the place of the heart, rather long in our first one (26 figures), is now limited to its essentials.
Daily concerns in critical care are mainly acute respiratory failure, acute circulatory failure, and cardiac arrest. The habit of looking at the heart in case of lung disease can be questioned: a lung approach is more direct. In the case of a circulatory failure, the FALLS-protocol shows that when one bases all of one’s calculations on the analysis of only one actor (the heart), this approach is direct only when the cause of shock is cardiac (what in passing the BLUE-protocol also detects using the lung approach). Adding the lung allows to keep the best of the simple heart. The amount of information “lost” in terms of Doppler or transesophageal echocardiography will possibly be compensated using precious data that lung ultrasound provides, mainly a direct parameter of clinical volemia.
So Still No Doppler in The Present Edition?
Dealing with echocardiography without mentioning Doppler or transesophageal approaches may appear bold today. Having accrued experience in a pioneering institution in echocardiography in the ICU since 1989 [1], the authors came to the temptive conclusion that therapeutic procedures can be deduced from the observation of simple phenomena. The integration of the lung gives birth to a new, holistic approach. The reader will therefore not take offense if TEE and Doppler do not feature.
Sophisticated echocardiography has a huge place in more quiet settings. Topics and terms such as Doppler physics, measurements of stroke volume and cardiac output, assessment of LV and RV function, measurement of filling pressures and of diastolic function, evaluation of valve function, determination of preload sensitivity and of intracardiac pressures, and identification of adverse subtle flow interactions, none of these terms is dealt with at the CEURF courses: LUCI allows to simplify echocardiography and provide a simple unit, easy to purchase everywhere, using the same single probe; this is, again, holistic ultrasound.
The reader must understand that during as long as necessary, the DIAFORA approach will be used. Here, a variant of DIAFORA will be used, “from inside,” i.e., by regular members of the ICU trained to echocardiography. We write and will repeat at the end that the ideal combination in any modern ICU is a comprehensive unit able of all cardiologic measurements and, beside, our simple unit as defined. This unit can be complementary in many settings to the usual cardiological approaches (read quietly Chaps. 20 and 30).
Do not forget that the expert echocardiographic approach is not an option for most patients on Earth.
Most figures come from a 1982 technology (ADR-4000®). Most figures of our previous editions have been deleted (see our 2010 Edition, or any classical echocardiography textbook).
The life-saving diagnoses made using the simple cardiac sonography can be made without compromise using our 5-MHz microconvex probe and our slim gray-scale machine.
At the Onset, Two Basic Questions
We raise two questions about cardiac sonography.
1.
How to see the heart is modestly described in this chapter (we don’t aim to teach a lot to experts). Today, the critical care physicians know where the right ventricle is, what is a dilated right ventricle, etc.
2.
Why do we want to see the heart is a more critical question, which should be answered in light of the emergence of lung ultrasound. As regards respiratory failure, this basic question will receive an answer in the BLUE-protocol (next chapter), showing that the diagnosis of pulmonary edema pertains to lung ultrasound. Facing circulatory failure, Chap. 30 will show that the look to the heart is indirect each time the cause is not cardiac. In the FALLS-protocol, after a simplified cardiac approach, lung ultrasound provides a direct parameter for fluid therapy. As regards cardiac arrest, the heart will come fifth in the SESAME-protocol (Chap. 31).
The Signs of Simple Emergency Cardiac Sonography Used in the BLUE-Protocol: What Is Required?
Nothing, since the BLUE-protocol uses lung and venous data. Echocardiographic data are associated to it, not included. LUCI provides a 97% sensitivity for diagnosing hemodynamic pulmonary edema. The Extended BLUE-protocol adds points using simple cardiac data.
The Signs of Simple Emergency Cardiac Sonography Used in the FALLS-Protocol: What Is Required?
The acute circulatory failure benefits first from a clinical examination, which usually provides a correct diagnosis. When no cause appears, the FALLS-protocol is initiated. It begins by the heart. This exploration is limited to two items: pericardial effusion and dilated right ventricle.
We therefore need to know which machine to use, which probe, where to apply the probe, how to understand the structures, and how to recognize the anomalies. The CEURF spirit will be used for simplifying this part.
Which Machine?
We use the same gray-scale unit used for the lungs, veins, abdomen, optic nerve, etc., a 1992 technology described in Chap. 2.
Which Probe?
We use the same probe used for the lungs, veins, abdomen, optic nerve, etc., a 1992 Japanese technology described in Chap. 2.
Where to Apply the Probe?
Traditional windows (parasternal, apical, subcostal, etc.) have been carefully defined. It is assumed today that intensivists, emergency physicians, etc., control these windows (see Appendix 1). Holistic ultrasound integrates them, but proposes an immediate, pragmatic solution when the windows are not perfect. The readers will see that the SESAME-protocol (Chap. 31) begins by the lung for the main reason that the fear not to find correct windows is absent from this first step.
As a critical detail, we do not spend high energy for having perfect cardiac windows, because we are not cardiologists, especially those working for other physicians (or even sonographists, who master this art). In the same way that you recognize a familiar face at first sight even if not strictly face/profile, you recognize the cardiac chambers. This critical detail makes simple cardiac sonography fully different to traditional echocardiography. The subcostal approach, very appreciated by intensivists in ventilated patients since often the only available, follows this philosophy: it offers a cardiac view of major interest even if truncated (Fig. 19.1).
Fig. 19.1
Subcostal view of the heart. This approach is a classic in the intensive care unit. It is a truncated equivalent of the four-chamber apical view of Fig. 19.2. RV right ventricle, RA right auricle, LV left ventricle, LA left auricle. The operator should move the probe from top to bottom (Carmen maneuver in fact) to acquire a correct three-dimensional representation of the volumes. The pericardium is virtual here
The apical approach gives at last the feeling that the heart, a complex organ, has a simple anatomy, since the ventricles are anterior (the auricles posterior) and the left chambers are at the right (the right chambers at the left). For once, things seem symmetrical (Fig. 19.2).
Fig. 19.2
Four-chamber view, apical window. Here, the heart seems to be a symmetric structure. LV left ventricle, LA left auricle, RV right ventricle, RA right auricle. This incidence allows immediate comparison of the volume and dynamics of each chamber. Note that the plane of the tricuspid valve is more anterior than the plane of the mitral valve. Right auricle and left ventricle are in contact (arrow), a detail which allows correct orientation
Countless details can help when windows are lacking. Wait for end-expiration to have a brief look to the heart. In the subcostal route, taking some liver tissue can increase cardiac image quality. The right parasternal route can show dilated right structures. When nothing works, the lung will answer many questions.
How to Understand the Structures?
The anatomy of the heart is complex. Those who will compare it to the rather simple ultrasound of the anatomy of the lung (just two signs) will make a step toward holistic ultrasound (the next step is to learn how far lung ultrasound answers to “cardiac questions”). Any echocardiographic textbook or costly simulators will show the cardiac structures. Ultrasound is a good way to understand, noninvasively, this anatomy.
Normal cardiac anatomy in 20 lines. The left ventricle is ovoid shaped, with a thick muscle and a long axis pointing leftward, downward, and forward. It has a base (where the aorta and, deeper, the left auricle are inserted), an apex, and four walls: inferior, lateral, anterior, and septal. The right ventricle has a more complex anatomy and is wounded around the left ventricle, with a thin free wall and a thick septal wall. Its volume assessment is subtle (due to its complex shape, novices taking a wrong plane will imagine enlargement where there is no enlargement). Its apex covers the septum; its base (infundibulum) covers the initial aorta. The main intracavitary structures are the valves and the left ventricular pillars. The auricles are visible behind the ventricles, yet, since we are not cardiologists, they are rarely of interest. The cardiac muscle is echoic. The chambers are anechoic. The pericardium is virtual.
Which Measurements?
In the spirit of simple emergency cardiac sonography, measurements are not of prime relevance. In addition, most intensivists have now been trained and know them. Read Appendix 2. Simple cardiac sonography is based on visual medicine.
How to Identify Cardiac Anomalies Pertaining to the FALLS-Protocol?
Pericardial Fluid
This is one of the most basic applications of critical ultrasound. It is life-threatening, easy to diagnose, and easy to treat. A circumferential pericardial effusion is detected when the external border of the heart is outlined by another, larger, external border, it is really simple to assess (Fig. 19.3). An equivalent of the sinusoid sign is found between the parietal and visceral layers of the pericardial sac during cardiac contractions. Usually anechoic, fluids can be echoic, septated (hemopericardium, purulent pericarditis) (Fig. 19.3), etc., and we avoid to define a pericardial effusion as an anechoic space, exactly like pleural effusions in the BLUE-protocol.
Fig. 19.3
The Excluded Patients of the BLUE-Protocol: Who Are They? Did Their Exclusion Limit Its Value?
The BLUE-Protocol and the Diagnosis of Pneumonia
Glossary
The Ultrasound Approach of an Acute Respiratory Failure: The BLUE-Protocol
The BLUE-Points: Three Points Allowing Standardization of a BLUE-Protocol
Which Equipment for the BLUE-Protocol 2. The Probe
Fluid collection in the pericardial space. The septations indicate an infectious cause. Note that the effusion (E) surrounds the entire heart: it is visible anterior to the left ventricle in this subcostal approach (smaller E). Pleuropericarditis due to pneumococcus
Related posts:
The Excluded Patients of the BLUE-Protocol: Who Are They? Did Their Exclusion Limit Its Value?
The BLUE-Protocol and the Diagnosis of Pneumonia
Glossary
The Ultrasound Approach of an Acute Respiratory Failure: The BLUE-Protocol
The BLUE-Points: Three Points Allowing Standardization of a BLUE-Protocol
Which Equipment for the BLUE-Protocol 2. The Probe
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