What Causes Tachycardia?

Patient Presentation
A 25-day-old male came to clinic because he seemed to be eating differently for the past 24 hours. His mother described it as less interested, but he still would breastfeed for 20-30 minutes every 2.5-3 hours, but seemed overall more tired. He had a good suck, didn’t turn blue or sweat during feedings, and maybe was slightly more tired in general. His crying was normal as were his urination and stooling. The mother didn’t think he was having pain, rhinorrhea, cough, or a rash.

The past medical history showed a healthy male born at 40 1/7 weeks gestation without problems. His neonatal screening and critical congenital heart disease tests were negative. He had regained his birth weight by 11 days of age. The family history was negative for any congenital heart disease or arrhythmias. He had a maternal aunt who had an early pregnancy spontaneous abortion. There were no abnormal deaths in the families. The review of systems was otherwise negative.

The pertinent physical exam showed a heart rate of 180-190 beats/minutes, respiratory rate of 36, temperature of 98.9°F, and eventually four-point blood pressures that were normal. His weight was 4.23 kg (50%) and length of 54 cm (50%). HEENT showed a normal fontanele and wet mucous membranes. His heart examination had a III/VI systolic murmur best at the mid-to-lower sternal border that could be heard on the back and axilla but it was difficult to discern because of the sustained tachycardia. Neck and head examinations for murmur radiation couldn’t be appropriately evaluated. Pulses in the upper extremities and lower extremities were normal. His capillary refill was brisk without obvious color changes. His lungs and abdomen were normal. There were no obvious congenital abnormalities on the rest of his examination.

The diagnosis of sustained tachycardia in the setting of a new heart murmur was made. The tachycardia varied between 170-190 beats/minute but mainly stayed in the 180’s range. It did vary with movement or crying of the neonate. The clinic evaluation included an electrocardiogram which showed sinus tachycardia and a chest radiograph which showed a normal heart size.

The patient’s clinical course revealed the patient was transferred to the emergency department for further evaluation where laboratory testing was negative, and the patient’s heart rate had decreased to the 150’s range. Pediatric cardiology was consulted and felt the patient could safely be seen the following day, where an echocardiogram showed a small muscular ventricular septal defect. A Holter monitor was placed with followup planned in 3 days.

Discussion
Tachycardia is a rapid heart rate that is above normal for age and level of exertion. Tachycardia is common, particularly sinus tachycardia due to normally encountered circumstances such as pain, fever or exercise. It is usually a normal physiologic process but sustained tachycardia often indicates a potentially abnormal underlying cause.

Sinus tachycardia has a rapid heart rate with normal P waves and P-R intervals and variations from moment to moment and respiration. Generally it is not over 200 beats/minute. Vagal stimulation can slow the heart rate; this is a gradual slowing, not an abrupt slowing seen in supraventricular tachycardia.

A supraventricular tachycardia has rapid fixed rates, and normal QRS complexes with no discernable P waves or P waves on top of T waves. Vagal stimulation causes no change or an abrupt change to sinus rhythm. Rates are usually 180-300 beats/minute.

Wide QRS complexes with usually a fixed rapid rate is a ventricular tachycardia but can also be a supraventricular tachycardia with ventricular aberration.

History always provides the primary context for evaluating tachycardia including recent illness, feeding problems, exercise or syncope, emotional state and especially medication use.

Physical examination should include evaluation of all vital signs with comparison to normal for age. Fever is commonly noted as can be dehydration when compared to previous weights. Four point blood pressures should be done if possible (congenital heart disease). Cardiac evaluation looking for distant heart sounds and/or pulseus paradoxus (pericardial effusion), S3 or S4 (cardiac dysfunction), and murmur (may be normal for state or are indicate underlying heart disease) can be helpful. Other physical examination findings may be helpful such as dry mucous membranes or prolonged capillary refill (dehydration), tachypnea and hepatomegaly (cardiac failure), poor perfusion (shock), pallor (anemia) and thyromegaly (hyperthyroidism).

Evaluation depends on history and physical examination but especially if a cardiac cause is suspected an electrocardiogram, chest radiograph and general laboratory testing (complete blood count, electrolytes, glucose, and calcium) usually are included in the initial testing. More extensive testing may be needed including echocardiogram, Holter monitoring, etc.

Treatment also depends on the underlying cause. It maybe as simple as calming an agitated patient, or treating a fever. But it can also be much more complicated with necessary specialty care, particularly cardiology.

Learning Point
The differential diagnosis of tachycardia includes:

  • Commonly encountered conditions
    • Anxiety
    • Crying
    • Dehydration
    • Exercise/exertion
    • Fever and/or infection
    • Medications – cough and cold medications, caffeine, legal or illegal drugs
    • Pain
  • Cardiac problems
    • Arrhythmias
      • Supraventricular tachycardia
      • Paroxysmal atrial tachycardia
      • Wolff-Parkinson White syndrome
      • Atrial fibrillation
      • Atrial flutter
      • Junctional tachycardia
      • Ventricular tachycardia
      • Ventricular fibrillation
    • Cardiac state, low or high output
      • Cardiac failure
      • Cardiomyopathy
      • Myocarditis
      • Hypertrophic cardiomyopathy
    • Pleural effusion
  • Other causes
    • Anaphylaxis
    • Anemia, acute or chronic
    • Acute rheumatic fever
    • Cancer
      • Cardiac tumors
      • Catecholine producing tumors
    • Drugs or toxins
      • Alpha-adrenergic agonists
      • Antiarrhythmics
      • Anticholinergics
      • Antidepressants
      • Antihistamines
      • Antimicrobials
      • Antipsychotics
      • Beta-blockers
      • Calcium channel blockers
      • Cardiac glycosides
      • Cholinergics
      • Opioids
      • Organophosphates
      • Sedative-hypnotics
      • Sympathomimetics
      • Arsenic
      • Citrate
      • Fluoride
      • Magnesium
      • Potassium
      • Thallium
      • Thyroid hormone
      • Carbon monoxide
      • Drug withdrawal
      • Caffeine
      • Tobacco
      • Herbals
    • Electrolyte disturbances
      • Hypoglycemia
      • Hypokalemia
      • Hypocalcemia
      • Hypomagnesemia
    • Hypoxemia
    • Hyperthyroidism
    • Kawasaki disease
    • Psychogenic, anxiety or other mental illness

Questions for Further Discussion
1. What are indications for an echocardiogram or Holter monitor?
2. What are indications for invasive treatment such as radioablation for an arrhythmia?
3. How is supraventricular tachycardia treated?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for these topics: Arrhythmias and Congenital Heart Defects

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Crosson JE, Callans DJ, Bradley DJ, et.al. PACES/HRS expert consensus statement on the evaluation and management of ventricular arrhythmias in the child with a structurally normal heart. Heart Rhythm. 2014 Sep;11(9):e55-78. doi: 10.1016/j.hrthm.2014.05.010.

Srinivasan C. Diagnosis and Acute Management of Tachyarrhythmias in Children. Indian J Pediatr. 2015;82(12):1157-1163. doi:10.1007/s12098-015-1881-5

Corwin DJ, Scarfone RJ. Supraventricular Tachycardia Associated With Severe Anemia: Pediatr Emerg Care. 2018;34(4):e75-e78. doi:10.1097/PEC.0000000000001134

Mazor S, Mazor R. Approach to the Child with Tachycardia. UpToDate. (rev. 3/2/2019, accessed 12/17/19).

Author
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa

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What Are Some Risk Factors for Cerebral Palsy?

Patient Presentation
A 5-year-old male came to clinic with increased spasticity for 2 days. He had underlying cerebral palsy and was wheelchair bound and non-verbal. His mother stated that he had not been crying or tearing but had increased spasticity and couldn’t seem to get comfortable. He had some rhinorrhea, but no cough, fever or rash. He had normal urination and had not had any hard stools using her normal bowel regimen. His mother said that when she bathed him she didn’t see any skin lesions or break down. His seizure pattern was also unchanged.

The past medical history showed he was a former 32-week premature infant who had a complicated neonatal intensive care stay. He was followed by multiple specialties including neurology, developmental disabilities, gastroenterology, and orthopaedics and he received comprehensive therapy services at school and in the community. The review of systems was not contributory.

The pertinent physical exam showed him posturing more than normal during the visit but there were times when he relaxed. His vital signs were normal, but a new weight was not obtained. His oxygen saturation was 97% on room air. HEENT showed clear rhinorrhea and a reddened pharynx without exudate but with palatal and peritonsilar vesicles. His ears were normal. Lungs, heart and abdomen were normal. His palms and soles had several 2-3 mm vesicles. There were no other lesions noted. His neurological examination showed increased spasticity in all extremities, but again he could relax at times. He was non-verbal but possibly reacted more during his HEENT examination.

The diagnosis of hand, foot and mouth disease was made. “It looks like he is having hand, foot and mouth infection. For some kids they don’t have many symptoms and for others they can have a lot. Maybe his mouth is bothering him more than we realize or he just plain doesn’t feel good. Why don’t we try to give him some ibuprofen on a schedule and see what happens. He doesn’t seem to be a lot more affected like he’s not having more seizures or doesn’t seem to have a second infection like an ear infection,” the pediatrician discussed. “Okay. He’s had an orthopaedic appointment to watch his hips and a wheel-chair fitting appointment in 2 days, so I could come back then if he’s not getting better,” the mother replied.

Discussion
The term, cerebral palsy, or CP has gone through many iterations with the first description in 1861 by W.J. Little who described it as “The condition of spastic rigidity of the limbs of newborn children.” The most recent definition is from Rosenbaun et al. in 2007 which states it is “a group of permanent disorders of the development of movement and posture, causing activity limitation, that are attributed to non-progressive disturbances that occurred in the developing fetal or infant brain. The motor disorders of cerebral palsy are often accompanied by disturbances of sensation, perception, cognition, communication, and behaviour, by epilepsy, and by secondary musculoskeletal problems.”

The incidence is about 2-3/1000 live births in high income countries but higher in low income countries. CP can be a severe motor problem for children and adults with up to 40% of patients unable to walk independently.

CP is really a clinical diagnosis with help from neuroimaging. It basically includes using history, some standardized physical examination ratings (i.e. Prechtl General Movement Assessment and Hammersmith Infant Neurological Examination), and cranial ultrasound or MRI which may show findings consistent with the history and physical examination such as intraventricular hemorrhage, cerebral or cerebellar hemorrhage, posthemorrhagic ventricular dilatation, or cystic periventricular leukomalacia. Diagnosis can be made within the first 6 months but this is usually in infants who have more problems. Patients are usually diagnosed after a year when the clinical trajectory of the patient and their individual problems are more consistent. This does not mean that a patient and family should wait for a diagnosis of CP to receive developmental surveillance and treatment if there are risk factors or concerns about the patient.

Any motoric area can be affected and subtypes are named for the area affected and how it is affected. For example, with predominantly the lower limbs (diplegia), the arm and leg on one side (hemiplegia) or all of the body (quadriplegia), and/or spasticity, dystonia (the two most common movement disorders with CP) and or dyskinesia.

The patient’s abnormal movements vary by the patient and the age. Patients with CP have a wide variety of comorbid problems, with the percentages given from high-income countries.

  • Chronic pain – 75%
  • Intellectual disability – 49%
  • Unable to walk independently – 40%
  • Epilepsy – 35%
  • Hip subluxation – 28%
  • Bladder control problems – 24%
  • Non-verbal – 23%
  • Sleep problems, pathological – 23%
  • Sialorrhea – 22%
  • Blind, functionally – 11%
  • Feeding tube requirement – 6%
  • Hearing impairment, severe 4%

Treatment includes managing the overall patient’s health, preventive services, specific services for their problems and early intervention services. Early intervention services are multidisciplinary services that focus on assisting the patient in all developmental areas including potentially physical therapy, occupational therapy, speech therapy, social interactions and cognitive interactions. Data more strongly supports benefits in cognition but less so for motor development. Other needs may include:

  • Spasticity and dystonia – physical therapy, occupational therapy, splinting, medications (i.e. Baclofen, Botulinum toxin A, Clonidine, Diazepam, Gabapentin), or neurosurgical interventions (i.e. selective dorsal rhizotomy, deep brain stimulation)
  • Hip dysplacement is common and needs ongoing screening particularly if the child is less mobile or immobile
  • Feeding and nutrition – difficulty swallowing, aspiration and drooling can be major problems for patients
  • Pain – this is common because of constipation, hip dislocation, spasticity and dystonia
  • Sleep disturbance – often because of other problems listed above, and may require behavioral interventions and medication

Learning Point
CP’s cause is not entirely known but appears to be multifactorial especially with accumulations of potential insults. Gestational age is a strong factor. Unfortunately for many of the risk factors, there are no easy or obvious treatments or preventive practices for them.

Rick factors for CP include:

  • Pregnancy
    • Genetics – higher risk in siblings particularly twins
    • Fetal growth restriction
    • Infections
    • Maternal obesity
    • Multiple births
    • Preeclapsia
    • Prolonged labor
    • Socioeconomic status, lower
  • Perinatal
    • Prematurity – 14.6% in gestation age 22-27 weeks, 6.2% in 28-31 weeks, 0.7% in 32-36 weeks, 0.11% in term infants
    • Post-maturity
    • Low birth weight
    • Small for gestational age
    • Birth defects
    • Birth complications – fetal bradycardia, low Apgar score, delayed time to first breath, breech position are some risk factors
    • Chorioamnionitis
    • Infection/inflammation
    • Kernicterus
    • Seizures
    • Stroke, perinatal
    • Abnormal neuroimaging findings
    • Post natal corticosteroid use
    • Early surgery
    • Mechanical ventilation
  • Protective factors for CP include:
    • Magnesium sulfate treatment for mother during pregnancy
    • Caffeine therapy for the infant
    • Brain or body cooling for the infant

    Questions for Further Discussion
    1. What are indications for referral to a developmental disabilities specialist?
    2. What does non-verbal mean? A review can be found here
    3. What is the classification for intraventricular hemorrhage? A review can be found here

    Related Cases

    To Learn More
    To view pediatric review articles on this topic from the past year check PubMed.

    Evidence-based medicine information on this topic can be found at SearchingPediatrics.com and the Cochrane Database of Systematic Reviews.

    Information prescriptions for patients can be found at MedlinePlus for this topic: Cerebral Palsy

    To view current news articles on this topic check Google News.

    To view images related to this topic check Google Images.

    To view videos related to this topic check YouTube Videos.

    Little W.J. Transaction of the Obstretrical Society of London. Longmans, Green and Co. 1862: 293-344.

    Spittle AJ, Morgan C, Olsen JE, Novak I, Cheong JLY. Early Diagnosis and Treatment of Cerebral Palsy in Children with a History of Preterm Birth. Clin Perinatol. 2018;45(3):409-420. doi:10.1016/j.clp.2018.05.011

    Graham D, Paget SP, Wimalasundera N. Current thinking in the health care management of children with cerebral palsy. Med J Aust. 2019;210(3):129-135. doi:10.5694/mja2.12106

    Korzeniewski SJ, Slaughter J, Lenski M, Haak P, Paneth N. The complex aetiology of cerebral palsy. Nat Rev Neurol. 2018;14(9):528-543. doi:10.1038/s41582-018-0043-6

    Lins LAB, Watkins CJ, Shore BJ. Natural History of Spastic Hip Disease. J Pediatr Orthop. 2019;39(Issue 6, Supplement 1 Suppl 1):S33-S37. doi:10.1097/BPO.0000000000001347

    Author
    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa

  • What Causes Neutropenia?

    Patient Presentation
    A 4-month-old female came to the emergency room with fever, poor feeding, fussiness and strong smelling urine. She had not been feeding well for 36 hours, with a decreasing number of diapers and increasing foul-smelling urine. The fever began about 18 hours previously and had ranged from 99.8°F to 102.3°F. Acetaminophen helped but the fever returned. She was crying more, and could be consoled but she appeared overall ill. She had 2 episodes of emesis just before coming to the emergency room but no diarrhea. Her parents denied any cough, rhinorrhea, or rashes other than her eczema.

    The past medical history showed a term-infant born without complications who had received appropriate preventative care including vaccinations. She had been diagnosed with atopic dermatitis 2 week previously. The family history was positive for heart disease and diarrhea. They denied any kidney disease or immune problems. The review of systems was otherwise negative.

    The pertinent physical exam revealed a tired and fussy infant who would calm with some effort. Her vital signs had a fever of 102.6° with tachycardia to 114 beats/min, respiratory rate of 26/min and an oxygen saturation of 100%. Her weight was down 250 grams from her visit 2 weeks ago, which was at the 50%. Her capillary refill was 2-3 seconds, with slightly dry mucous membranes. Her fontanelle was normal. Her skin showed dry reddened areas in the flexural areas and behind her ears, and general xerosis of her trunk and cheeks. Her examination was otherwise well. Her diaper smelled foul.

    The laboratory evaluation showed a catheterized urinalysis of 1.025 specific gravity, many white blood cells, some red blood cells with positive nitrites and leukocyte esterase. Her complete blood count showed a hemoglobin of 10.6 x 1000/mm2, white blood cell count of 5.2 x 1000/mm2 with only 1350 neutrophils. Her platelets were 360 x 1000/mm2. The rest of her complete blood count was normal as a complete metabolic profile. Her C-reactive protein was elevated at 2.7 mg/dl.

    The diagnosis of a urinary tract infection and potential bacteremia was made. She was admitted for intravenous fluids, antibiotics and monitoring. The patient’s clinical course showed that she improved with treatment and was discharged at 48 hours. The blood culture was negative. Her urine culture grew Escherichia coli that was pansensitive to antibiotics and she was sent home on oral antibiotics. An ultrasound of her kidneys was normal before discharge. Her complete blood count still showed mild neutropenia at 1475 at discharge. Her C-reactive protein had decreased to 1.8 mg/dl. At her one week followup appointment her neutropenia and complete blood count were normal. At her one year well-child examination, her complete blood count was normal and she had not had any other urinary tract infections.

    Discussion
    Neuropenia is defined as a neutrophil count < 1500/µL. It is classified as mild from 1000-1500/µL, moderate from 500-1000/µL, and severe if < 500/µL.

    It is not uncommonly seen in the setting of acute self-limited infections, and with re-testing returns to normal. It is also not uncommon at certain ages, such as perinatally, especially in premature infants (up to 6%) . It is also common in certain ethnic groups particularly African American or Arabic populations where up to 10% of the children may have mild neutropenia which does not cause clinical disease. The overall prevalence and incidence are not known but some studies estimate it at 2 per million persons.

    Neutropenia can be thought of as an acute problem due to rapid neutrophil use or destruction, or decreased production of neutrophils. Chronic neutropenia is due to decreased production or splenic sequestration.

    Neutropenia can also be thought of as a primary or intrinsic problem due to primary myeloid cell production or an intrinsic defects. Secondary or acquired causes of neutropenia are usually due to infections, immune response, bone marrow infiltration or drugs.

    Clinical signs or symptoms of potential neutropenia include fever, oral ulcers, upper airway infections (e.g. otitis media, pharyngitis, sinusitis), respiratory (e.g. pneumonias) or perianal infections. Skin infections like cellulitis, paronychia, or furunculosis may also indicate neutropenia. Bacteremia or sepsis are also potential clinical indications. Recurrent or complicated infections or infections with unusual organisms may indicate neutropenia. Other systems can also be affected.

    Treatment depends on the underlying cause with antibiotics, general support, discontinuation of potential iatrogenic causes, and granulocyte stimulating medications if appropriate.

    Learning Point
    The differential diagnosis of neutropenia includes:

    • Age or ethnic-related
      • Premature infant
      • Newborn infant
      • African American or Arabic ethnicity
    • Infection
    • Congenital or hereditary neutropenia
      • ELANE mutations
        • Cyclic neutropenia – generally 21 day cycles between normal and abnormal neutrophil counts
        • Severe congenital neutropenia
      • Non-syndromic
        • Autosomal dominant severe congenital neutropenia
          • Kostman syndrome
        • Autosomal recessive severe congential neutropenia
          • Wiskott Aldrich syndrome
        • X-linked neutropenia
      • Other syndromic
        • G6PC3 deficiency
        • Barth syndrome
        • Cohen syndrome
      • Bone marrow insufficiency
        • Dyskeratosis congenital
        • GATA2 deficiency
        • Fanconi anemia
      • Combined immunodeficiency
        • XHIGMS
        • WHIM syndrome
        • Reticular dysgenesis
      • Metabolic disease
        • Glycogen storage disease 1b
        • Isovaleric acidemia
        • Methylmalonic acidemia
        • Propionic acidemia
      • Oculocutaneous hypopigmentation
        • Chediak-Higashi syndrome
        • Griscell syndrome type 2
        • Hermansky Pudlak syndrome type 2
        • p14 deficiency
      • Pancreatic insufficiency
        • Schwachman-Diamond syndrome
        • Pearson marrow syndrome
    • Drug related
      • Antibiotics
      • Alcohol
      • Chemotherapy
    • Immune mediated
      • Neonatal alloimmune – transplacental transfer of maternal antibodies to paternal antigen
      • Neonatal isoimmune neutropenia – transplacental transfer of existing maternal IgG antibodies
      • Autoimmune – probably triggered by viral infections or environmental antigens
      • AIDS
    • Myelodysplasia
      • Bone marrow infiltration or replacement
        • Leukemias
        • Dysgammaglobulinemia
    • Other
      • Folate or Vitamin B12 deficiency
      • Hypersplenism or splenic sequestration

    Questions for Further Discussion
    1. What are common presentations for primary immunodeficiencies? A review can be found here

    2. What are different fever patterns and what are their potential problems? A review can be found here

    3. What is in the differential diagnosis of lymphocytosis? A review can be found here
    4. What are potential complications of acute pyelonephritis? A review can be found here
    5. How do you treat fever and neutropenia due to chemotherapy?

    Related Cases

    To Learn More
    To view pediatric review articles on this topic from the past year check PubMed.

    Evidence-based medicine information on this topic can be found at SearchingPediatrics.com and the Cochrane Database of Systematic Reviews.

    Information prescriptions for patients can be found at MedlinePlus for these topics: Urinary Tract Infections, Blood Disorders and Immune System and Disorders.

    To view current news articles on this topic check Google News.

    To view images related to this topic check Google Images.

    To view videos related to this topic check YouTube Videos.

    Neutropenia – Hematology and Oncology. Merck Manuals Professional Edition. https://www.merckmanuals.com/professional/hematology-and-oncology/leukopenias/neutropenia?query=neutropenia. Accessed December 3, 2019.

    Dale DC. How I manage children with neutropenia. Br J Haematol. 2017;178(3):351-363. doi:10.1111/bjh.14677

    Kebudi R, Kizilocak H. Febrile Neutropenia in Children with Cancer: Approach to Diagnosis and Treatment. Curr Pediatr Rev. 2018;14:204-209.

    Spoor J, Farajifard H, Rezaei N. Congenital neutropenia and primary immunodeficiency diseases. Crit Rev Oncol Hematol. 2019;133:149-162. doi:10.1016/j.critrevonc.2018.10.003

    Author
    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa