What is the Menstrual Cycle?
Menstruation is a monthly process that, in women with uterus and ovaries, takes place between puberty and menopause. It prepares the body every month for a possible pregnancy. The womb (uterus), together with the ovaries, assesses whether sperm has fertilised an egg [1, 2].
The menstrual cycle is divided into four phases: the menstrual phase, the follicular phase, the ovulation phase, and the luteal phase. Hormonal shifts and corresponding physical processes are specific to each of these phases. When the egg released during ovulation is not fertilised, the built-up uterine lining is pushed out of the body and a period, or menstruation, is triggered [3].
The delicate tissue is controlled by an enticing endocrine and paracrine environment that regulates and coordinates the menstrual cycle, culminating in an orchestrated sequence of hormone secretions that mark the start and end of each menstrual segment. For example, ovulation, maturation and rupture of the follicle, and the stimulation of other key hormones are mostly triggered by the elevation of luteinising hormone (LH) [4].
Menstrual blood, a mix of blood and parts of the uterine lining, leaves the body via the vagina. A cycle is usually from the last day of the period to the first day of the period; that is, 28 days, although bleeding usually lasts for just 4-5 days [5, 6].
Aside from reproduction, the menstrual cycle also transmits other information. Its monthly rhythms are a valuable vital sign of general health. Disorders and dysfunctions can be indicated by large variations in the menstrual cycle [7].
What are Heart Palpitations?
Heart Palpitations are feelings that your heart is skipping a beat, beating an extra time, or beating too fast or too slow (inconsistent heartbeats). They can feel like fluttering, racing, bounding or pounding. They can be felt in your chest, throat or neck. Palpitations are often benign, go away without treatment, and aren’t caused by any underlying medical condition. But palpitations can also be a symptom of a more serious condition [8].
What Causes Heart Palpitations?
There are multiple causes of the sensations of uneven heartbeats, ranging from strong emotions to lifestyle factors. For example, strong feelings like elation or panic leading to common temporary causes of palpitations include strenuous exercise, caffeine or alcohol intake, nicotine from tobacco, sleep deprivation, dehydration, stress, anxiety or fear, and certain medications. Heart palpitations are associated with almost all diseases affecting the heart [8].
Alongside these non-heart-related causes, Heart Palpitations can be caused by medical conditions affecting the heart: arrhythmia (irregular heart rhythm); abnormal heart valves, heart disease, congestive heart failure, heart-related infections, or overactive thyroid (hyperthyroidism). Other conditions, such as fever, sleep apnoea, electrolyte abnormalities, lack of sufficient oxygen or too much carbon dioxide in the blood, blood loss, anaemia and low blood sugar levels can also lead to Heart Palpitations [8, 9].
Hormones and Heart Palpitations
Hormonal changes associated with the menstrual cycle can lead to heart palpitations. Oestrogen is the hormone that increases with the follicular phase of the menstrual cycle (the part of a woman’s cycle before ovulation) and falls during the luteal phase (the part of a woman’s cycle after ovulation). Women have reported higher incidences of Heart Palpitations during this time. During menopause when women experience drastic changes in estrogen levels, they report an increase in palpitations, particularly during hot flashes: during a hot flash, a woman’s heart may increase by 8 to 16 beats per minute [10].
These are also common when other periods of intense hormone flux occur – such as the menstrual cycle and pregnancy. For example, palpitations are particularly frequent in women during the luteal phase of the menstrual cycle (the second part of the cycle, between ovulation and menstruation) [11].
Can the Menstrual Cycle Cause Heart Palpitations?
Heart palpitations can be part of the menstrual cycle. Heart palpitations feel like your heart is beating unusually fast or irregularly as if you have just run very fast or very long. Your heart might feel like it skipped a beat or flutters and this pounding sometimes travels up to your neck and throat [10].
The phases of the menstrual cycle can also interact with the occurrence of Heart Palpitations. Women experience these sensations most frequently at all ages; specifically, during the luteal phase in the menstrual cycle, during pregnancy, and during the perimenopausal period [11].
The hormone oestrogen undergoes fluctuation throughout the menstrual cycle, and changing oestrogen levels can trigger Heart Palpitations. Women can be plagued by palpitations any time hormone levels shift, such as around their periods or even during their pregnancy [10].
During the luteal phase of the menstrual cycle, sympathetic nervous activity increases and Heart Palpitations are more common [12, 13].
However, it is also known that anything that disturbs the pattern of the menstrual cycle – such as stress, exercise, caffeine, alcohol and nicotine, some medications, fever, irregular heart rhythms, thyroid conditions, hypoglycaemia, a drop in blood pressure and dehydration – can also cause Heart Palpitations [10].