Approach to palpitations in primary care

Opening Vignette

Ms. Tan, a 30-year-old teacher, visited your clinic with complaints of intermittent episodes of racing heartbeat for the past 3 months. The episodes would occur and resolve spontaneously and lasted 5–10 min each time. She was worried, as her father had passed away from a heart attack at the age of 55. She wanted to know if she needed a cardiologist review.

WHAT ARE PALPITATIONS?

Palpitations are an unpleasant awareness of the beating of the heart, which some patients might describe as ‘racing’, ‘pounding’, ‘flopping’, ‘skipping’, ‘thumping’ or ‘fluttering’ of the heart.[1] Some of the common causes include cardiac disorders, endocrine and metabolic abnormalities, medications, substances such as illicit drugs, alcohol, caffeine and tobacco, and psychiatric conditions.

HOW COMMON IS THIS IN MY PRACTICE?

Palpitation is one of the most common symptoms in primary care, accounting for about 16% of the presenting complaints in general practice.[2,3] In a cardiologist’s clinic, it is the second most common complaint after chest pain.[3] A prospective cohort study by Weber and Kapoor[4] identified underlying aetiologies in 84% of the 190 patients presenting with palpitations to a university medical centre’s emergency department, inpatient service or outpatient clinic, of which 43% were attributed to cardiac causes, 31% to anxiety or panic attack/disorder, 6% to illicit drugs, prescription or over-the-counter medications, and the remaining 4% to noncardiac medical causes.

HOW RELEVANT IS THIS TO MY PRACTICE?

Palpitations, while being relatively common, may sometimes be a cause of concern, as they can be a manifestation of life-threatening cardiac or noncardiac pathologies. Many patients who present with palpitations are concerned about an underlying cardiac cause. While certain diagnoses might be straightforward, some may prove challenging due to a myriad or paucity of accompanying symptoms.[4] Nevertheless, studies have found palpitations to be associated with low mortality and cardiac morbidity in the outpatient setting.[4,5,6,7] However, patients with persistent symptoms have higher psychological symptoms, role impairment and healthcare utilisation.[6] Therefore, the role of general practitioners is to evaluate palpitations in a cost-effective and evidence-based manner, tease out potential serious and life-threatening causes to ensure right siting of care, and control symptoms with appropriate therapy to reduce psychological burden and impairment of activities.

WHAT CAN I DO IN MY PRACTICE?

As palpitations can be caused by a variety of conditions, it is critical to approach the symptom systematically. This section will outline the important diagnostic considerations in evaluating palpitations and key points in the clinical assessment.

An indispensable component of the evaluation of palpitations is looking for a cardiac cause, which can arise from ischaemia or electrical conduction defect, which gives rise to dysrhythmias or structural abnormality. Dysrhythmias or abnormal rhythms could be either fast (tachydysrhythmias) or slow (bradydysrhythmias), which can either be regular or irregular, and can be better characterised with electrocardiography. The second important cause of palpitations is drugs and substances. Use of caffeine, tobacco, alcohol or sympathomimetics is known to cause palpitations. Cessation of a sympatholytic, such as beta-blockers, can likewise cause palpitations. The third group includes conditions that contribute to systemic stress, such as hypovolaemic state, pregnancy, anaemia, fever, sepsis, pulmonary embolism, electrolyte disturbances and endocrinopathies. Important endocrine conditions include hypoglycaemia, hyperthyroidism and, more rarely, phaeochromocytoma/paragangliomas and Paget’s disease. Fourthly, neurological abnormalities that affect the autonomic nervous system may give rise to palpitations, such as vasovagal syndrome and postural orthostatic tachycardia syndrome (POTS). Lastly, psychological conditions, such as anxiety and panic attacks/disorders, are another common group of conditions accounting for palpitations in the general practice. The list of conditions is shown in Box 1.

Box 1.

Causes of palpitations.

Cardiac: arrhythmia

• Atrial fibrillation/flutter

• Bradycardia caused by arteriovenous block or sinus node dysfunction

• Brugada syndrome

• Multifocal atrial tachycardia

• Premature supraventricular or ventricular contractions

• Sinus tachycardia or arrhythmia

• Supraventricular tachycardia

• Ventricular tachycardia

• Wolf-Parkinson-White syndrome/long QT syndrome

• Pacemaker-mediated tachycardia

Cardiac: structure

• Atrial or ventricular septal defect

• Atrial myxoma

• Cardiomyopathy

• Congenital heart disease

• Congestive cardiac failure

• Valvular disease (mitral valve prolapse, aortic insufficiency, aortic stenosis)

Drugs medication, toxins

• Alcohol

• Tobacco/nicotine

• Caffeine

• Illicit drugs (cocaine, amphetamines, anabolic steroids, marijuana, ecstasy, heroin)

• Prescription medications (beta agonists, theophylline, digitalis, phenothiazine, steroids, methylphenidate, midodrine, epinephrine, anticholinergics)

• Over-the-counter medications (pseudoephedrine, omega-3-polyunsaturated fatty acids, coenzyme Q10, carnitine)• Withdrawal of medications (beta-blockers)

Physiologic

• Exercise

• Fever

• Hypovolaemia/dehydration

• Pregnancy

Endocrinologic

• Hyperthyroidism

• Hypoglycaemia

• Paget disease of the bone

• Phaeochromocytoma

Haematologic

• Anaemia

• Mastocytosis

Psychological

• Anxiety, stress

• Panic attacks

Neurologic

• Autonomic dysfunction

• Vasaovagal syndrome

• Postural orthostatic tachycardia syndrome

Others

• Electrolyte imbalance

• Pulmonary disease

Clinical history

Characterisation of palpitations

• 1.Rate and rhythm: How would you describe the palpitation? Was it fast or slow? Was it regular or irregular? Did it skip a bit? Could you tap if for me?

‘Flip-flopping’ in the chest, ‘pounding’ or very strong heartbeat followed by heart briefly stopping may be caused by premature supraventricular or ventricular beats.[8] Tachycardiac palpitations are described as ‘beating wings’ in the chest, usually with rapid onset and offset, suggesting supraventricular or ventricular tachydysrhythmias.[9] They can be triggered by exertion or cooling down and have a markedly accelerated rate, which can be regular or irregular. They can also be associated with symptoms such as syncope, fatigue, dyspnoea or chest pain. Tachycardiac palpitations can also be caused by drugs and systemic stressors such as fever, anaemia, thyrotoxicosis and others, but their onset and offset tend to be more gradual.[9] Regular and rapid pounding sensation in the neck increases the likelihood that palpitation is due to atrioventricular node re-entry tachycardia (AVNRT) (likelihood ratio [LR] 177; 95% confidence interval [CI] 25–1251), whereas its absence makes it less likely (LR 0.07; 95% CI 0.03–0.19).[10] Extrasystolic palpitation is described as a sensation of ‘skipping a beat’ or ‘heart sinking’. It generally carries a benign prognosis.[9] Found in young subjects, often in the absence of heart disease, it is usually characterised by normal heart beats interspersed with ectopics, during which the heart seems to stop and then restart, causing an unpleasant sensation of a blow to the chest. Anxiety-related palpitations, on the other hand, tend to have slightly elevated heart rate but not above the age-related maximum heart rate, and may have associated symptoms of tingling, sensation of lump in the throat, agitation, sighing dyspnoea, and so on. With the rising prevalence of smart watches, it might be useful to ask if the patient owns one and managed to get the heart rate during the episode or captured the rhythm.

• 2.Triggers and circumstances: What were you doing when the palpitations came on?

As mentioned earlier, tachydysrhythmias can cause tachycardiac palpitations; these entities tend to have sudden onset and are triggered by exertion, which is generally a more worrisome descriptor. Cardiac causes are also more likely when palpitations occur at work or wake one from sleep, with the LRs in studies by Summerton et al.[11] and Thavendiranathan et al.[10] being 2.17 (95% CI 1.19–3.96) and 2.29 (95% CI 1.33–3.94), respectively. Patients with atrioventricular re-entrant tachycardia (AVRT) and AVNRT can experience palpitation episodes triggered by postural changes, with a sensation of rapid regular pulsation in the neck, which can sometimes also be visible.[9,12] Cardiac dysrhythmias, such as vagal nerve-mediated ventricular premature contraction, can also occur at rest.[13] On the other hand, palpitations arising in situations of stress favour anxiety as a cause.

• 3.Onset and duration: When did the palpitations start? Did they start suddenly or gradually? How long did they last?

Weber and Kapoor[4] found that palpitations lasting less than 5 min make a cardiac cause less likely (LR 0.38; 95% CI 0.22–0.63).[8] Sustained palpitations, lasting for minutes (or longer), are more consistent with supraventricular arrhythmias, ventricular arrhythmias or anxiety.[13] Patients with palpitations on a regular basis were more than twice as likely to have a significant cardiac arrhythmia as a cause for their palpitations versus those who did not describe any regularity to their palpitations.[14]

Associated symptoms

Palpitations associated with syncope or other symptoms, such as severe fatigue, dyspnoea or angina, feature more frequently in patients with structural heart disease, although syncope may also occur at the onset of supraventricular tachycardia in a structurally normal heart as a result of vasovagal response.[15,16] In tachydysrhythmias arising from an atrial origin, atrial natriureticpeptide may be elevated and cause patients to develop polyuria.[16]

Cardiac risk factors

Personal history of cardiac disease, including structural and electrical pathologies, should be sought, particularly, coronary artery disease, in an older adult. A systematic review[10] showed that known history of cardiac disease makes a cardiac cause of palpitations more likely (LR 2.03; 95% CI 1.33–3.11). Family history of cardiac disease, tachycardia and sudden cardiac death are also critical components in history taking, especially in younger subjects.

Substances and medications

It is important to obtain a thorough history beyond the prescribed list of active and recently stopped medications. One should also assess if the patient is taking the correct dose at an appropriate timing and, in the case of an elderly, if anyone is supervising medication administration. Caffeine and alcohol consumption should be documented and quantified. Supplements, over-the-counter prescriptions and traditional medications may contain ingredients that can cause palpitations either directly or as a side effect. Palpitations due to nasal decongestants with pseudoephedrine, omega-3-polyunsaturated fatty acids, coenzyme Q10 and carnitine have been reported.[17] With the right demographics, illicit substance abuse should also be considered.

Systemic, neurological and psychiatric conditions

Many systemic disturbances can increase metabolic demands and stimulate higher cardiac output. Conditions such as hypovolaemia, anaemia, fever and pregnancy can induce chronotropic and inotropic effects, which can result in palpitations. Additionally, conditions such as sepsis, hypoglycaemia, hyperthyroidism and phaeochromocytoma can stimulate increased cardiac output by adrenergic means, thereby causing palpitations. It is important to assess these pathologies in the assessment of palpitations. As anxiety is the most common noncardiac cause of palpitation,[18] having a good assessment of a patient’s past medical history is crucial. Known history of panic disorder (LR 0.26; 95% CI 0.07–1.01) makes a cardiac cause less likely.[10]

Physical examination

Unfortunately, as palpitations are usually intermittent and short-lived, patients may be asymptomatic with minimal signs or no yield from physical examination during the clinical consultation. A complete physical assessment should still be undertaken, and this includes vital signs with orthostatic readings as postural fluctuations may hint at an underlying cardiac pathology, hypovolaemia, sepsis, or even rarer causes such as autonomic dysfunction or POTS. Palpation of the pulse may discover an underlying abnormal rhythm such as atrial fibrillation. Cardiovascular examination could reveal underlying structural causes such as clicks or murmurs for mitral valve prolapse or hypertrophic obstructive cardiomyopathy, features of heart failure or pulmonary hypertension, and so on. One should also assess other systems such as the abdominal or thyroid system if there are features suggestive of anaemia or hyperthyroidism, respectively. In a busy primary care setting, anxiety should be screened using simple tools such as Generalised Anxiety Disorder 2-item.

Investigations

After a thorough history and physical examination, a 12-lead electrocardiogram (ECG) should be performed to exclude cardiac cause. All patients presenting with palpitations should be evaluated for an ischaemic cause[19] or arrhythmia. Nonspecific ST-segment and T wave changes in symptomatic patients should not be considered normal but should prompt further evaluation for a cardiac cause. Targeted laboratory investigations such as full blood count, thyroid function test and electrolytes can be ordered if there are suggestive features based on clinical assessment.

WHEN SHOULD I REFER TO A SPECIALIST?

A specialist referral should be considered for suspected cardiac causes of palpitations [Box 2]. In the event that there is no obvious cause of palpitations, but the patient remains symptomatic regularly and persistently, a 24-h Holter study can be arranged. If palpitations occur during the period when Holter is worn, there is a high possibility of correlating symptom to the heart rhythm captured.[20] However, if no palpitation or symptom occurs during the 24-h period, Holter may not be useful for diagnostic purposes and further investigations may be required. Patients with recurrent vasovagal syncope should undergo tilt-table testing.[20] For those with clinical findings suggestive of underlying cardiac structural cause or heart failure, a transthoracic echocardiogram should be considered.

Box 2.

Indications for specialist referral.

• Symptoms suggestive of underlying ischaemic heart disease: angina/angina equivalent

• Symptoms suggestive of underlying cardiac arrhythmias: sustained/frequent palpitations, syncope

• Electrocardiographic findings of ischaemia

• Electrocardiographic findings of Wolff-Parkinson-White, long/short QT, supraventricular tachydysrhythmias, ventricular tachydysrhythmias, atrial flutter, atrial fibrillation

• High-risk individuals: patients with congenital heart disease, family history of recurrent syncope or sudden cardiac death, complex structural heart disease

MANAGEMENT IN THE PRIMARY CARE SETTING FOR COMMON CAUSES OF PALPITATIONS

Therapy should be directed towards the aetiology. In many benign arrhythmias (e.g. premature beats), a number of general factors may modulate the frequency and severity of the symptoms.[3] In this context, changes in lifestyle (e.g. restraining adrenergic substances such as caffeine or alcohol-containing beverages) or noncardiologic therapies (e.g. anxiolytic drugs or psychiatric counselling) may be useful to control symptoms and should be considered.[3] At times, reassurance of the patient on the benign nature of the disorder can markedly reduce symptoms. Good control of cardiovascular risk factors, specifically hypertension, should be ensured. Specialist referral for further investigation is warranted if there are any red flags.

TAKE HOME MESSAGES

1. Palpitations are one of the most common complaints in the general practice but are associated with low mortality and cardiac morbidity in the outpatient setting.

2. Eighty-four percent of the cases have an identified aetiology, with 43% attributed to cardiac causes and 31% due to anxiety or panic attack/disorder.

3. Common causes include cardiac conditions, drugs and substances, systemic stress, endocrine conditions or neurological abnormalities. Psychological symptoms and psychiatric conditions are diagnoses of exclusion.

4. Patients should be encouraged to monitor their heart rate during palpitation using a pulse oximeter or smart watch.

5. It is important to characterise the palpitations in terms of rate and rhythm, onset and duration, triggers and circumstances, associated symptoms, cardiac risk factors, medications, systemic illnesses, neurological conditions and psychological symptoms.

6. A complete physical examination should include vital signs with orthostatic readings, cardiovascular examination, features of systemic illnesses like anaemia and hyperthyroidism, and anxiety assessment.

7. A 12-lead ECG should be performed to exclude ischaemia or arrhythmia, and targeted laboratory investigations can be ordered if there are suggestive features based on clinical assessment.

8. If there is no obvious cause and the patient remains symptomatic regularly and persistently, a 24-h Holter study can be considered.

9. Patients should be referred to a specialist if they have palpitations with concurrent symptoms suggestive of ischaemic heart disease or cardiac arrhythmia, significant personal or family history of cardiac disease, sudden cardiac death, recurrent syncope or abnormal ECG findings.

Closing Vignette

Ms. Tan was initially fearful of her palpitations and insistent on getting a specialist review. After a detailed discussion with her general practitioner, she acknowledged that she was stressed at work due to the upcoming national exams and had been taking five cups of coffee daily to mark exam scripts past midnight. Her resting heart rate was regular, at 70 beats per minute with no orthostatic changes, and her ECG was normal. She was given lifestyle modification advice and offered community counselling services. Ms. Tan’s frequency of palpitations improved significantly after reducing her caffeine intake and receiving counselling from her school counsellor.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

SMC CATEGORY 3B CME PROGRAMME

Online Quiz: https://www.sma.org.sg/cme-programme

Deadline for submission: 6 pm, 06 August 2024

Question: Answer True or False

1. More than 80% of palpitations are due to cardiac causes.

2. Endocrine causes are the second most common aetiologies of palpitations.

3. Psychological causes are diagnoses of exclusion.

4. Comprehensive history taking of substances and medications is important in the evaluation of palpitations.

5. Patients with atrioventricular re-entrant tachycardia and atrioventricular node re-entrant tachycardia can experience palpitation episodes triggered by postural changes and have a sensation of rapid regular pulsation in the neck, which can also be visible sometimes.

6. Sustained palpitations, lasting for minutes (or longer), are more consistent with supraventricular arrhythmias, ventricular arrhythmias or anxiety.

7. In a patient with tachydysrhythmia, polyuria, if present, may suggest an atrial source due to excess atrial natriuretic peptide.

8. Known personal history of cardiac disease makes a cardiac cause of palpitations more likely and warrants a referral to a specialist.

9. Family history of recurrent syncope, sudden cardiac death and ischaemic heart disease are important risk factors for referral to a specialist.

10.Palpitations can be caused by nasal decongestants with pseudoephedrine, omega-3-polyunsaturated fatty acids, coenzyme Q10 and carnitine.

11. History of alcohol and caffeine intake is required in the assessment of palpitations.

12. Pregnancy is not a systemic cause of palpitations.

13. Anxiety is the most common noncardiac cause of palpitations.

14. Postural fluctuations may hint at an underlying cardiac pathology, hypovolaemic states, sepsis, or even rarer causes such as autonomic dysfunction or postural orthostatic tachycardia syndrome.

15. All patients with palpitations should be evaluated with an electrocardiogram.

16. All patients with palpitations should undergo a 24-h Holter monitoring if the electrocardiogram is normal.

17. All patients with palpitations should go for transthoracic echocardiogram if there are no signs of heart failure or structural heart disease.

18. Targeted laboratory investigations should be performed for patients with palpitations with suggestive features in clinical assessment.

19. Nonspecific T wave changes or ST changes on electrocardiogram in symptomatic patients should be considered abnormal and warrant a specialist referral.

20. Patient Health Questionnaire 2 is a screening tool for anxiety in primary care.