Complications of Rheumatic Heart Disease and Acute Emergencies

Introduction

The clinical course of both acute rheumatic fever (ARF) and rheumatic heart disease (RHD) may be complicated by acute life-threatening conditions. This chapter will focus on: (1) the clinical evaluation, diagnosis, and management of acute heart failure (AHF); (2) infective endocarditis (IE); and (3) the management of overanticoagulation and bleeding in patients receiving oral anticoagulation. The etiology and pathophysiology of AHF in rheumatic carditis is discussed in Chapter 3 . Chronic heart failure (HF) is discussed in detail in Chapter 5, Chapter 6 and the management of RHD and HF in pregnancy is discussed in Chapter 9 .

1: Acute Heart Failure

Definition and Classification

The main clinical syndrome resulting in death and disability in both ARF and RHD is HF, the natural history of which is characterized by episodes of acute decompensation (AHF). AHF is broadly defined as a potentially life-threatening syndrome, characterized by a rapid onset of new or worsening signs and symptoms of HF that typically requires urgent medical attention.

The development of AHF as a consequence of ARF or RHD is challenging. Some patients develop an acute deterioration in valvular function, where the presentation is usually dramatic and potentially life threatening. In certain cases, however, clinical features suggesting a valvular cause of AHF may be subtle, for example, the regurgitant murmur in acute severe mitral or aortic regurgitation is often soft and difficult to hear. Successful management requires maintaining a high index of suspicion, appropriate hemodynamic assessment, and timely initiation of therapeutic options. In most cases, however, AHF results from chronic valvular disease with progressive deterioration in ventricular function, often culminating in repeated subacute presentations requiring hospitalization. Treatment may be challenging, particularly in resource-limited populations as patients are often deprived of access to valve surgery, the only intervention that improves outcomes. Despite this, optimal medical treatment will usually provide symptomatic improvement in the short term.

Although characterized by a common set of signs and symptoms, AHF is a syndrome rather than a single disease entity, and patients exhibit a wide spectrum of features ( Box 16.1 ). Moreover, while our understanding of chronic HF has improved considerably over the last 20–30 years, the presentation and management of AHF is less well understood. Nonetheless, admission to hospital with AHF is a significant prognostic event in the natural history of ARF or RHD, indicating that not only is the valve lesion important but also that an additional factor may have contributed to the clinical picture. For many patients, it also indicates a poor prognosis, with a high risk of readmission and death postdischarge.

Box 16.1

Classification of Acute Heart Failure

AHF may present as a first occurrence ( de novo AHF) or as a consequence of acute decompensation of chronic HF (ADHF).

De Novo Acute Heart Failure

Occurs in patients with advanced RHD
Constitutes 70% of patients hospitalized for AHF in nonendemic populations
Causes: (1) primary cardiac dysfunction (usually worsening left ventricular function); (2) precipitated by extrinsic factors
Typical presentation: with mild-to-moderate signs and symptoms of congestion and fluid retention
Acuity: subacute over days to weeks (chronic neurohormonal compensatory mechanisms and preexisting medical therapy help ameliorate the severity of presentation)

Acute Decompensated Heart Failure

In ARF:
- -
  Usually subacute presentation with some cardiac enlargement and compensation
- -
  Sometimes presents as fulminant carditis (see Chapter 3 , Chapter 4 ). In acute severe MR, the LA is noncompliant and acute pulmonary edema occurs within days
In RHD: as a first presentation of chronic valve disease

Epidemiology

A global epidemiological profile for AHF has emerged over the last 2 decades. Although most of the data originate from high-income countries (HICs), little is known about AHF in low- and middle-income countries (LMICs), where ARF and RHD are endemic.

In the landmark 1950s publication by Bland and Duckett Jones, a 20-year analysis of 1000 patients showed HF to account for 80% of all deaths from RHD. Cardiac enlargement early in life (presumably during the phase of ARF) had the strongest correlate with mortality, suggesting that the development of HF during ARF carries an extremely poor prognosis. In the contemporary REMEDY study (prospective registry, 3343 patients with RHD), congestive HF was the most frequent complication, and was seen in 33.4% of the patients. In addition, 25% of adults and 5.3% of children had reduced ejection fraction, and left ventricular (LV) dilatation occurred in 23% and 14.1%, respectively. Sixty percent of patients had multivalvular disease, and 66.7% of these were severely affected.

The sub-Saharan African Study of Heart Failure (THESUS-HF) was the first (and to date, only) prospective, observational survey that characterized the causes and short-term outcomes of African adult patients with AHF. Here, 1006 patients with AHF (mean age 52 years) were recruited from 12 university hospitals in nine African countries between 2007 and 2010. In contrast to data from HICs, the etiology of AHF in these patients was predominantly nonischemic, with hypertension (45.4%), idiopathic dilated cardiomyopathy (18.8%), and RHD (14.3%) accounting for 75.5% of cases. AHF presented around 2 decades earlier than in those patients from Europe and the United States. In-hospital mortality was 4.2% and estimated 180-day mortality was 17.8%, which were comparable to non-African registries. In a subanalysis of patients enrolled in THESUS-HF with RHD from South Africa, the 60-day mortality after admission with AHF due to RHD was 24.8% (95% CI 13.6%–42.5%) and 180-day mortality was 35.4% (95% CI 21.6%–54.4%). The epidemiology of HF due to RHD is discussed further in Chapter 1 .

Etiology of Acute Heart Failure

Acute rheumatic fever

A full discussion on the mechanisms of AHF in rheumatic carditis is presented in Chapter 3 . In brief, acute severe mitral or mitral and aortic regurgitation (all secondary to valvulitis) are by far the most common causes of AHF in those who develop ARF. Rarely, chordae tendineae rupture (causing acute severe mitral regurgitation) or cardiac tamponade are the primary cause of AHF. Rheumatic myocarditis does not on its own cause significant myocardial dysfunction and AHF, unlike other forms of myocarditis ( Table 16.1 ).

Table 16.1

Key Differentiating Features Between Rheumatic Carditis and Viral Myocarditis.

	Acute Rheumatic Carditis	Acute Viral Myocarditis
Age (years)	Usually 5–15	Any age
Epidemiology	Usually in areas where ARF is endemic	Anywhere
Prodrome	Sore throat	Headache, myalgia, skin rash, gastroenteritis, coryza
Cardiac murmurs	Murmurs of MR, AR	Nil or flow murmur
Hypotension	Unusual	Common
ECG	Prolonged PR interval or advanced AV block Accelerated junctional tachycardia	Low-voltage QRS complexes Bundle branch block Tachyarrhythmias, including ventricular tachycardia Risk of sudden cardiac death
Echocardiography	Significant mitral and/or aortic regurgitation	Mild to moderate secondary mitral regurgitation
LV Ejection Fraction	Normal or increased	Decreased
Troponin T	Normal	Elevated
Serology or PCR	ASOT positive Anti-DNAse B positive	Parvovirus, Coxsackie, Echo, Herpes, adenovirus, influenza, parechovirus, enterovirus
Cardiac magnetic resonance	Minimal changes	Often abnormal especially on T2 mapping
Endomyocardial biopsy	Nonspecific. May have aschoff bodies	Myocarditis Lymphocytic inflammation, myocyte degeneration

AR, aortic regurgitation; ARF, acute rheumatic fever; ASOT, antistreptolysin O titer; AV, atrioventricular; ECG, electrocardiogram; LV, left ventricular; MR, mitral regurgitation; PCR, polymerase chain reaction.

Rheumatic heart disease

In contrast to those with ARF, patients with established RHD have chronic valvular heart disease. When the valve disease is significant, this is often accompanied by varying degrees of LV dysfunction and remodeling similar to that seen in nonrheumatic disease. The valvular lesions in RHD patients also tend to be more complex than those seen in ARF, with mixed and multivalve disease being the most common phenotype. RHD patients are also usually older and may suffer from significant comorbidities. They may require long-term medical therapy and have undergone mechanical or surgical valvular intervention.

The causes of AHF in those with RHD are therefore broad and are detailed in Box 16.2 . In many patients, an episode of AHF is often the result of numerous interlinked factors but in 40%–50% of all admissions, no clear precipitant is found.

Box 16.2

Factors Triggering Acute Heart Failure in Rheumatic Heart Disease

Valve-related

Natural history of chronic, severe valve regurgitation causing myocardial (pump) failure
Recurrent acute rheumatic fever
Infective endocarditis
Acute prosthetic valve syndrome
- Dehiscence (e.g., infective endocarditis)
- Thrombosis (most often causing stenosis)
- Structural failure (e.g., tear or perforation of a bioprosthetic valve)
Iatrogenic mitral regurgitation following percutaneous mitral balloon commissurotomy

Nonvalvular

Tachyarrhythmia (e.g., atrial fibrillation, ventricular tachycardia)
Acute rise in blood pressure or chronic hypertension
Worsening renal failure
Infection (e.g., pneumonia, sepsis, influenza)
Anemia
Pregnancy and peripartum-related disorders
Nonadherence (e.g., medications, salt/fluid intake)
Acute coronary syndrome
Cerebrovascular insult
Pulmonary embolism
Heavy alcohol consumption
Noncardiac surgery and perioperative complications

Evaluation and Management of the Patient With Acute Heart Failure

The diagnostic work-up of AHF should start in the prehospital setting and continue in the emergency department. Given the potentially life-threatening nature of AHF, establishing a definitive diagnosis of the underlying cause, with initiation of appropriate therapy as rapidly and efficiently as possible, are of key importance as time to initiation of treatment is linked to outcome.

In all acutely unwell patients, a systematic approach is essential. Fig. 16.1 presents an algorithmic approach to the initial evaluation of patients with suspected AHF from the latest HF guidelines of the European Society of Cardiology (ESC). This algorithm highlights four phases, detailed later:

(1)
early recognition, treatment, and triage of life-threatening conditions (i.e., respiratory failure and cardiogenic shock)
(2)
early recognition and treatment of any acute etiology or relevant triggers requiring specific treatment (e.g., acute valvular regurgitation, arrhythmia, pericardial tamponade)
(3)
completing the diagnostic work-up of AHF once the patient is stable
(4)
defining the clinical profile of the patient to rapidly select the most appropriate therapy

Fig. 16.1, Algorithm for initial evaluation and management of patients with suspected acute heart failure. AHF, acute heart failure; BiPAP, bi-level positive airway pressure; CCU, coronary care unit; CPAP, continuous positive airway pressure; ESC, European Society of Cardiology; ICU, intensive care unit.

Each of these phases will be discussed in order in the following sections. However, as stated in Box 16.1 , most patients with ARF or RHD that develop AHF will present subacutely and many of the therapeutic strategies in phases I and II will not be necessary. Most patients will therefore enter the treatment algorithm at phase III.

Phase I: Early recognition, treatment, and triage of life-threatening conditions

Initial evaluation begins with an ABC assessment (airway, breathing, and circulation) while simultaneously taking a focused history and progressing toward diagnosis and treatment ( Box 16.3 ).

Box 16.3

ABC Assessment of the Unwell Patient

ABC, airway, breathing, and circulation; ABG, arterial blood gas; AHF, acute heart failure; ARF, acute rheumatic fever; CXR, chest X-ray; ECG, electrocardiogram; HF, heart failure; NYHA, New York Heart Association; RHD, rheumatic heart disease; SpO2, peripheral oxygen saturation.

Complete the ABC Assessment While Taking a Focused History:

Any chest pain, dizziness, palpitations?
Symptoms of AHF and duration
Severity of breathlessness (NYHA class—see Chapter 5 )
Previous history of ARF/RHD/HF; previous cardiac surgery or hospitalizations
Drug history, including any recent changes and adherence
Any dietary change, including salt and water intake?
Any change in urine output?

Airway

Look for and treat any evidence of airway obstruction (simple airway maneuvers, airway adjuncts, intubation)

Breathing

Look for signs of increased respiratory effort and/or ineffective respiration (e.g., inability to complete sentences, confusion)
Tachypnea (>upper limit of normal for age of patient) is a sensitive and reliable marker of critical illness
Give oxygen only if S _p O ₂ is <90% (in all adults or children with respiratory distress) or if S _p O ₂ is <94% in children with signs of shock ± respiratory distress
Examine the chest for signs of cardiac congestion (crackles, cardiac wheeze, pleural effusion)
Order an urgent CXR (and ABG if unable to acquire a reliable S _p O ₂ reading)
Consider lung ultrasound (interstitial edema, pleural effusion)

Circulation

Assess the limbs for temperature (warm or cool) and check central capillary refill time in the sternal area (prolonged if >2 s in adults or >3 s in children)
Palpate the pulse rate and rhythm, measure the blood pressure, and examine the JVP
Listen to the heart sounds, record an ECG, and attach a cardiac monitor
Assess for peripheral congestion (e.g., sacral and lower limb edema, hepatomegaly)
Insert one or more wide-bore (depending on the age of the patient) cannulae and send urgent labs
Monitor urine output, use catheter if necessary (aim >0.5 mL/kg/h)

The key elements of airway and breathing assessment are ensuring airway patency and determining the need for supplemental oxygen and respiratory support ( Table 16.2 ). Continuous pulse oximetry (S _p O ₂ ) is mandatory. Although some degree of pulmonary edema is common in AHF, severe pulmonary edema only occurs in <3% of all AHF presentations. Oxygen should not be used routinely in AHF as it may cause hyperoxia-induced vasoconstriction and reduced cardiac output. Oxygen is a treatment for hypoxemia and not breathlessness and does not consistently alter the sensation of breathlessness in nonhypoxemic patients. Intravenous (IV) morphine (for patients with severe anxiety or distress) should be used cautiously (if at all), particularly in those with hypotension, bradycardia, advanced heart block, or hypercapnia. Where concern arises, senior anesthetic/intensive care input is required.

Table 16.2

Oxygen and Ventilatory Support for Respiratory Failure due to Acute Heart Failure . ^a

Treatment	Indications	Comment
Oxygen	Hypoxemia: - S _p O ₂ <90% or P _a O ₂ <8 KPa (<60 mmHg) in all adults and children with respiratory distress - S _p O ₂ <94% in children with shock	Target S _p O ₂ : 90%–96%: - If S _p O ₂ <85%: use reservoir mask (15 L/min) ^b
Continuous positive airway pressure (CPAP)	Oxygenation failure: S _p O ₂ <90% (or S _p O ₂ <94% in shocked children), despite adequate oxygen therapy (F _i O ₂ >40%)	Initiate at a PEEP of 5–7.5 cmH ₂ O and titrate to 10 cmH ₂ O as needed
Non-invasive ventilation (NIV)	Ventilatory failure: P _a CO ₂ >6.1 KPa (>46 mmHg) and pH < 7.35	Initiate at an IPAP 8–10 cmH ₂ O and EPAP 4 cmH ₂ O. Increase IPEP in 2–3 cmH ₂ O increments to a maximum of 25 cmH ₂ O
Endotracheal intubation and mechanical ventilation	Impending respiratory arrest (reduced GCS, pH <7.25, RR >35) or if oxygenation or ventilatory failure cannot be managed noninvasively	May not be appropriate if cardiac disorder is not remediable or patient is not a candidate for CPR

PEEP, positive end-expiratory pressure; IPAP, inspiratory positive airway pressure; EPAP, expiratory positive airway pressure; CPR cardiopulmonary resuscitation; GCS, Glasgow coma score.

a Settings need to be standardized according to weight and age of the patient. Close observation and repeated re-evaluation of the patient are important, with timely escalation or deescalation of therapy as appropriate.

b Severe heart failure in children should also be treated with high flow nasal prong therapy, either in the ward or intensive care setting.

If hypoxemia persists despite adequate oxygen therapy (F _i O ₂ >40%), continuous positive airway pressure (CPAP) or noninvasive ventilation (NIV), delivered through tight-fitting face masks, should be given ( Table 16.2 ). Both improve respiratory mechanics and unload the left ventricle (LV) by decreasing afterload. Because CPAP provides less inspiratory support (i.e., it is not a true ventilation modality) than NIV, the latter is more useful in the most severe patients (hypercapnic pulmonary edema, or respiratory fatigue). Meta-analyses and randomized controlled trials have shown that both CPAP and NIV decrease the need for intubation and improve physiological parameters (heart rate, dyspnea, hypercapnia, and acidemia), although there is conflicting evidence regarding their impact on mortality. Both should be used cautiously if the patient is hypotensive (systolic blood pressure (SBP) <90 mmHg) and should be avoided in cardiogenic shock.

Assessment of the circulation is aimed at identifying hemodynamic instability and evidence of cardiogenic shock. Only a minority of adult patients with AHF present with an SBP <90 mmHg (<8%) or cardiogenic shock (<3%); most present with a preserved (90–140 mmHg) or elevated (≥140 mmHg) SBP. ESC guidelines define cardiogenic shock in adults as an SBP <90 mmHg (with adequate volume) with clinical (cold extremities, oliguria, mental confusion, dizziness, and narrow pulse pressure) or laboratory (metabolic acidemia, elevated serum lactate, elevated serum creatinine) evidence of hypoperfusion.

In children, the clinical diagnosis of shock can be challenging, particularly in resource-limited settings. The 2016 emergency triage, assessment, and treatment guidelines developed by the World Health Organization (specifically for use in resource-limited settings) define shock as cold extremities with a capillary refill time >3 s and a weak, fast pulse (all signs must be present). When only one of these signs is present (i.e., capillary refill time >3 s or a weak, fast pulse or cold extremities), the patient meets the definition of “severely impaired circulation.” Patients with ARF (e.g., acute severe valvular regurgitation) or RHD (e.g., low output advanced end-stage chronic HF) may present with cardiogenic shock.

The initial management of adults and children with cardiogenic shock is summarized in Box 16.4 . Fluid resuscitation in patients with cardiogenic shock should only be indicated in those without pulmonary edema. Isotonic crystalloids such as normal saline or Lactated Ringer's should be administered slowly to decrease the likelihood of exacerbating HF.

Box 16.4

Initial Management of Cardiogenic Shock in Adults and Children

SBP, systolic blood pressure; IV, intravenous; BP, blood pressure.

Adults

1.
IV fluid challenge only if no evidence of pulmonary edema
- Give 500 mL isotonic crystalloid over 15 min
- Repeat once if SBP remains <90 mmHg without evidence of pulmonary edema
2.
IV vasoactive agents only if SBP remains <90 mmHg despite adequate filling and treatment of immediately reversible causes (see phase II)
- See Tables 16.3 and 16.4 for type and indication of vasoactive agent
3.
IV diuretics should be considered if evidence of fluid overload once cardiac input has improved
- Give furosemide 40 mg IV bolus if the renal function is normal (consider higher doses if renal dysfunction)
- Other patients that might benefit from diuretics are those who are “wet and cold” (see phase IV) and with a “normal” BP, that is, not meeting the definition of cardiogenic shock

Children

1.
IV fluid challenge: same principles as for adults
- Give 5–10 mL/kg over 10–20 min
- Target Perfusion and SBP: 70 mmHg + [2 × age in years] in children 1 month–10 years; ≥90 mmHg in children ≥10 years old
2.
IV vasoactive agents: same principles as for adults (with age-adjusted BP targets)
- See Tables 16.3 and 16.4 for type and indication of vasoactive agent
3.
IV diuretics: same principles as for adults
- Give 1 mg/kg IV bolus

Vasoactive agents ( Tables 16.3 and 16.4 ) represent “rescue therapy” in cardiogenic shock. They are used to stabilize and salvage, or as a bridge to nonpharmacological management such as mechanical circulatory support (MCS), surgery, or transplantation. None of these agents improve outcomes and some may increase mortality. Because of these concerns, ESC guidelines restrict their use only in those who fulfill the definition of cardiogenic shock or in those who are symptomatically hypotensive. Given that there is no robust evidence base, choice of vasoactive agent often differs between institutions.

Table 16.3

Mechanism of Action and Hemodynamic Effects of Common Vasoactive Medications Used in Cardiogenic Shock.

Reproduced with permission from van Diepen S et al.

Medication	Usual Infusion Dose	Receptor Binding				Hemodynamic Effects
Medication	Usual Infusion Dose	α ₁	β ₁	β ₂	Dopamine	Hemodynamic Effects
Inotropes/Vasopressors
Dopamine	0.5–2 μg/kg/min	–	+	–	+++	↑ CO
	5–10 μg/kg/min	+	+++	+	++	↑↑ CO, ↑ SVR
	10–20 μg/kg/min	+++	++	–	++	↑↑ SVR, ↑ CO
Norepinephrine	0.05–0.4 μg/kg/min	++++	++	+	–	↑↑ SVR, ↑ CO
Epinephrine	0.01–0.5 μg/kg/min	++++	++++	+++	–	↑↑ CO, ↑↑ SVR
Phenylephrine	0.1–10 μg/kg/min	+++	–	–	–	↑↑ SVR
Vasopressin	0.02–0.04 U/min	Stimulates V ₁ receptors in VSM				↑↑ SVR
Inodilators (Inotrope That Reduces Peripheral Vascular Resistance)
Dobutamine	2.5–20 μg/kg/min	+	++++	++	–	↑↑ CO, ↓ SVR, ↓ PVR
Isoproterenol	2–20 μg/min	–	++++	+++	–	↑↑CO, ↓ SVR, ↓ PVR
Milrinone	0.125–0.75 μg/kg/min	PDE III inhibitor				↑CO, ↓ SVR, ↓ PVR
Levosimendan	0.05–0.2 μg/kg/min	Myofilament Ca ²⁺ sensitizer, PD-3 inhibitor				↑CO, ↓ SVR, ↓ PVR

CO, cardiac output; SVR, systemic vascular resistance; PVR, pulmonary vascular resistance; PDE, phosphodiesterase III; VSM, vascular smooth muscle.

Diuretics are relatively ineffective in cardiogenic shock and should generally be avoided. However, diuretics can be used in fluid-overloaded patients receiving vasoactive agents who demonstrate evidence of improved cardiac output (e.g., improved SBP >90 mmHg, mental state, skin perfusion). Vasodilators are also often contraindicated in cardiogenic shock, although can be considered if the SBP has improved to ≥100 mmHg following treatment. The use of diuretics and vasodilators in AHF are discussed in detail in phase IV.

Immediate echocardiography is mandatory in patients with suspected cardiogenic shock (see also phase II). In addition to helping to confirm the underlying diagnosis, it can also help guide the need for IV fluids (preload insufficiency) and triage to more targeted medical therapy ( Table 16.4 ) or surgical intervention (e.g., emergency surgery for chordal rupture with a flail leaflet). A standard 12-lead ECG and continuous telemetry are also essential and may reveal a tachy- or bradyarrhythmia or myocardial ischemia, warranting an early invasive approach such as electrical cardioversion, pacing, or primary percutaneous coronary intervention. ECG and blood pressure monitoring are also recommended during inotrope/vasopressor use as they can cause arrhythmias and myocardial ischemia. Urine output should always be measured because it provides an assessment of the effectiveness of therapy, and an indirect measure of cardiac and renal function.

Table 16.4

Initial Vasoactive and Mechanical Management in Types of Cardiogenic Shock Most Relevant to Acute Rheumatic Fever or Rheumatic Heart Disease.

Adapted from van Diepen S et al.

Cause of Cardiogenic Shock	Vasoactive Management	Hemodynamic Rationale
Left Ventricular Dysfunction	Dobutamine or milrinone or other PDE III inhibitor Norepinephrine or higher dose dopamine (>5 μg/kg/min) Temporary MCS	Inodilator is used to increase cardiac output, increase BP, improve peripheral perfusion, and maintain end-organ perfusion Vasopressor added to inodilator if ongoing hypotension
Mitral Regurgitation	Norepinephrine or dopamine Dobutamine or milrinone Temporary MCS, including IABP	Vasopressor, although 1st line, may worsen degree of MR by increasing afterload If impaired LV contractility and ongoing hypotension, add inodilator IABP may reduce regurgitation fraction by reducing afterload and increasing CI
Mitral Stenosis	Phenylephrine or vasopressin Esmolol or amiodarone Electrical cardioversion PMBC	Shock resulting from MS is a preload-dependent state Aim to slow the HR and maintain atrioventricular synchrony Avoid agents that increase HR
Aortic Regurgitation	Dopamine Temporary pacing	Maintain an elevated HR (to shorten diastolic filling time and reduce LVEDP)
Aortic Stenosis	Phenylephrine or vasopressin If LVEF reduced, echo- or PAC-guided dobutamine titration	Shock caused by AS is an afterload-dependent state Inotropes may not improve hemodynamics if LVEF is preserved
Bradycardia	Chronotropic agents (atropine, isoproterenol, dopamine) Temporary pacing	Advanced heart block due to rheumatic carditis rarely (if ever) requires temporary pacing
Pericardial Tamponade	Fluid bolus Norepinephrine	Pericardiocentesis or surgical pericardial window required for definitive therapy

AS, aortic stenosis; CI, cardiac index; BP, blood pressure; HR, heart rate; IABP, intraaortic balloon pump; LV, left ventricular; LVEF, left ventricular ejection fraction; LVEDP, left ventricular end-diastolic pressure; MCS, mechanical circulatory support; MS, mitral stenosis; MR, mitral regurgitation; PAC, pulmonary artery catheter; PMBC, percutaneous mitral balloon commissurotomy; PDE III, phosphodiesterase III.

Routine invasive hemodynamic evaluation, arterial line, or central venous line for diagnostic purposes are not indicated, but may be helpful in selected patients who are hemodynamically unstable with an unknown mechanism of deterioration.

Early warning scores, for both adults and children, are used in many HICs and some LMICs to identify deranged physiology as early as possible, thus prompting review by senior medical staff and/or admission to an intensive care setting ( Box 16.5 ). A combination of heart rate, respiratory rate, oxygen saturations, capillary refill time, and level of consciousness are more useful than a single parameter. In units where high-flow respiratory therapy is restricted to ICU, this would also be an indication for earlier transfer.

Box 16.5

European Society of Cardiology Criteria for Admission to the Coronary Care or Intensive Care Unit in Adults ^a

^a Similar criteria should be used for children but with pediatric cutoffs for physiological variables.

Need for intubation (or already intubated)
Signs and symptoms of hypoperfusion
S _p O ₂ <90%, despite supplemental oxygen
Use of accessory muscles for breathing, respiratory rate >25 breaths/min
Heart rate <40 beats/min or >130 beats/min, systolic blood pressure <90 mmHg

In those who remain critically unwell despite respiratory and pharmacological intervention, MCS, if available, such as the intraaortic balloon pump (IABP), extracorporeal membrane oxygenation (ECMO), or ventricular assist devices can help achieve temporary stabilization before emergency surgery for valve repair or replacement. ECMO has been used successfully in the treatment of respiratory failure or cardiogenic shock resulting from fulminant rheumatic valvulitis. IABP is contraindicated in those with significant (more than mild) aortic regurgitation (AR) because it augments aortic diastolic pressures and worsens the severity of the regurgitant volume.

In many resource-limited settings, access to most of these monitoring and treatment modalities is not available. Patients are also more likely to present late in their illness, thus requiring more intensive and specialized intervention early in the management course. Malnourishment, severe anemia, and an increased background prevalence of infectious agents, such as falciparum malaria and tuberculous, often complicate management. These factors must be taken into consideration when tailoring the administration of fluids, blood products, and vasoactive medications. First-line vasoactive agents in resource-limited settings will vary depending on local protocols and drug availability, although a useful consideration is that dobutamine can be given through a peripheral line in settings where central line access is not available.

Phase II: Identification and treatment of acute etiologies or relevant triggers of AHF

As mentioned earlier, in patients presenting with suspected AHF secondary to ARF, it is important to consider acute valvular regurgitation. Factors that may trigger AHF in patients with RHD are summarized in Box 16.2 . Immediate bedside echocardiography is necessary in patients who are either hemodynamically unstable or in patients with a suspected life -threatening mechanical pathology. Box 16.6 summarizes the key elements in the echocardiographic evaluation of the acutely unwell patient with suspected AHF. Transthoracic echocardiography is usually sufficient for diagnosis by demonstrating the underlying mechanism. If inconclusive, transesophageal echocardiography usually clarifies the diagnosis and underlying mechanism and may be used in the planning of operative repair.

Box 16.6

Echocardiogram in a Patient With Acute Heart Failure and Shock: Checklist

LV, left ventricle; RWMA, regional wall motion abnormality; MR, mitral regurgitation; MS, mitral stenosis; AR, aortic regurgitation; IE, infective endocarditis.

Assess LV systolic function (and ideally LV size, presence of RWMAs)
Valves
- exclude MR, MS, or AR
- exclude IE, flail leaflet
- assess prosthetic valve function
Exclude pericardial effusion
Assess right ventricular size and function
Estimate right atrial and pulmonary artery pressures

Acute valvular regurgitation

The medical management for organic causes of acute MR and acute AR leading to AHF is broadly similar. Diuretics and bed rest may be all that is required in patients with AHF secondary to severe valvular regurgitation as a consequence of acute rheumatic valvulitis. Most of these patients will stabilise over hours to days. Some experts also recommend corticosteroids in these patients, despite the absence of high-quality evidence (see Chapter 4 ). Diuretics and vasodilators (discussed in phase IV, later) help reduce left-ventricular end-diastolic pressure and provide symptomatic relief. Vasodilators also reduce afterload and can improve forward cardiac output. Their use may be limited by systemic hypotension, and it may be necessary to commence inotropes first to achieve a satisfactory blood pressure.

Nitroprusside (see phase IV) is the vasodilator of choice in both acute MR and AR, although it is used in fewer than 1% of patients with AHF in Europe and the United States. In acute MR, nitroprusside may reduce MR by up to 50%. Because the determinants of the regurgitant volume in acute AR include the duration of diastole and the diastolic transvalvular gradient, it is important to avoid bradycardia and arterial hypertension where possible.

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