A single blood pressure reading at the doctor’s often says little. Nervousness can push it up – this is known as white coat hypertension. Conversely, raised blood pressure in everyday life can hide behind normal readings at the practice. Ambulatory blood pressure monitoring clarifies both: a small device on your belt inflates a cuff on your upper arm at fixed intervals, day and night, and stores every reading.
The evaluation looks at the average values over 24 hours, while awake and during sleep. According to the recommendations of the European Society of Hypertension, which the German Hypertension League has adopted, a 24-hour average of 130/80 mmHg or more indicates high blood pressure, as does an average of 135/85 or more while awake or 120/70 mmHg or more during sleep. Normally, blood pressure falls by at least ten per cent at night. If this dip does not occur, that is a finding in its own right.
A pacemaker gives the heart an impulse as soon as its own rhythm becomes too slow or stops. The device, about five centimetres in size, usually sits below the collarbone and is connected to the heart by one or more leads. It works on its own for years. But to make sure the battery, leads and settings continue to meet the heart’s needs, it requires regular checks.
During the check, a programmer reads out the data wirelessly, usually via a programming head placed on the skin over the device. It checks the battery level, the condition of the leads and the stimulation threshold – the smallest amount of energy that still reliably stimulates the heart. Stored events such as episodes of atrial fibrillation are analysed. After the first check in the weeks following implantation, appointments usually follow every six to twelve months, and more often towards the end of the battery’s life. Many systems can also be monitored remotely. Implanted defibrillators are checked on the same principle, often at shorter intervals.